Comprehensive Introduction to API Testing Fundamentals and Tools

okay so hi everyone uh welcome you all uh from  today we are going to start APA testing classes   and as part of today's session uh we are going  to see the fundamentals like uh what is an API   and what kind of testings we do on part as  part of API testing and before discussing  

about API testing we have to know some Basics  about what is client what is server and how   exactly web applications Works internally right  so we need to have some basic knowledge on web   testing also to before starting API testing  okay and in the today's session we will see  

some Basics we will understand we will try  to understand some basic concepts and then   we will try to understand what is an API testing  and how we can conduct AP testing and what are   the different tools are available in the market  to perform API testing okay so that's a basic  

introduction part today we are going to see  and at the end of the session uh if you have   any questions you can ask me and mean file you can  use chart window to post all your questions okay   so first of all let us see the basic like what  is web application so what is actually software  

a software can be an application which is  developed for specific client or specific   customer right so software application software  is an application which is developed for specific   client or some customer or sometimes the software  can be developed based on the market requirement  

also and which is basically called as a products  right so where exactly API testing come into   picture so there are various types of testing  we will conduct on software like web testing API   Testing mobile app testing performance testing  security testing there are so many types of  

testings normally we do on software so why we  need to do all these kinds of testing because   we need to release the quality product or quality  software to the customer so that's the main end   goal right so APA is also one of the testing API  testing is also one of the testing which is very  

very important to do the software but normally uh  web testing we will know what is web testing means   we will test that application and functionality  we will test with respect to customer requirement   whether it is working according to customer  requirement or not the functional device we will  

test on the web UI but what is an API means API  is basically the API testing we will conduct at   the backend side so we don't see anything on the  UI so we will do APA testing and the backend side   so which is basically comes under backend testing  like API testing database testing so these things  

comes under backend testing not a front-end  and web testing is comes under the front end   okay web testing so we have also different tools  are available in the market like to perform web   testing we use selenium normally and to perform  APA testing we use Postman and rest ratio so  

bi and so many tools are there in the market so  different for different type of testings we have   a different tools are available in the market and  for API testing also we can do manually and also   we can do automatically and to perform manual API  testing normally we use a tool called Postman and  

then to perform automation testing we will use  a rest assured okay so one is a manual testing   tool the other one is an automation testing so as  part of this course we are going to learn both so   first we will learn Postman tool and a few days  we will try to understand what is Postman how  

to use Postman how we can test apis manually  by using Postman and what are the different   features are there in the postman so we'll try to  understand and we will practically test all the   apis by using Postman tool and once you understand  manual testing of apis then we will move on to the  

automation part that is rest assured so in the  rest I showed we will try to automate the apis   and to automate apis using rest assured the  main prerequisite is what you have to know   a Java Basics Java programming Basics and then  you should also know some basics of test engine  

framework okay so if you learn web testing uh  these two things will be part of your web testing   okay and even if you don't know test NG no problem  but at least we have to know some Java Basics okay   how we can write a simple Java program if you know  some basics of java you can easily understand this  

okay and it is very easy to learn also and  even web testing is something trickier than   API testing and you can easily learn API testing  and very simple and very easy to learn only thing   is you need to know some basic Java Concepts  okay so let us try to understand some basics of  

web applications and then we will discuss more  about what is an API and what are the different   testings we will conduct as product API and so on  okay so first we will see a manual testing of apis   using Postman tool and once you understand the  replay testing using manual process then we will  

try to learn automating apis by using rest ratio  so these are the two tools which are part of our   sessions okay so let me share a small presentation  and to understand about web applications and so on   and very important session so because if you  are not understood these sessions or these are  

important points then it is very difficult to  understand the rest of the things okay yeah so   Java Basics are not part of the session so it's  not part of this course okay you have to already   and if you don't know Java Basics so please go  through my free sessions which are available on  

my YouTube channel and you can understand  some Basics and people who are already   attended psyllium sessions and who already  know Java Basics and they are enough okay   all right so first of all let us see what is  client and server so these two terminologies we  

use normally while working with the web-based  applications client and the server so what is   client and what is server a simple understanding  is server means what which contains the actual   application so which contains a actual application  or software will run on the server and we will  

able to access through the client client is  nothing but what from where we are accessing   the application right so for example on the web  application suppose you are typing google.com   and we are able to access Google pages from the  server and we are not those pages are not coming  

from your local system right so they are coming  from somewhere else and we are trying to access   them through browser right so from where you  are trying to access that is called as a client   from where actually the software is installed  or from where exactly the web pages are uh still  

exist that is basically called as a server  okay so the definitions wise a client is   a computer hardware device or a software that  accesses a service made available by the server   so the definitions are little bit tricky  but simple way to understanding is  

a client is a a computer or from where we are  trying to access the application so for example   through browser we are able to browse the  different pages different websites we are able to   access and that is comes under the client so from  where we are trying to access the applications  

that is called as a client and actually where the  applications are installed from where we are able   to exactly accessing that is basically called as  a server and between the client and server we need   a connection so through internet we are able to  establish a connection to the server and then we  

are able to access it so the basic understanding  client and the server the client means what we   are all clients because we are able to access  the application through browser that's a client   and from where exactly we are getting those  pages you are browsing so much of information  

in the internet from where we are getting all that  information where exactly that available is in the   server and sometimes these servers many times  the servers will be in the remote locations for   remote environment okay but in some organizations  uh they will also keep the servers in this local  

environment but normally in the internet uh the  servers will be there in the remote environment   so we will able to access them through URLs okay  so through your answer so for example just we   are browsing some website right so when I say  google.com it is just sending some request here  

and immediately I'm getting the page right  so here we are accessing the application by   passing some URL by sending some URL and this  is a client as a user I'm able to access the   applications through browser this is a client and  from where we are getting these pages from where  

we are getting all this information where exactly  these information is available that is called as   a server and when you send some requests to the  server in the form of URL which will give us to   response the server will respond with some data  okay for example here I'm typing uh let's say APA  

testing I'm searching for something so I got all  these pages so from where I got all these Pages   the server is respond to us so how why server is  respond to us because we are sending the request   when you're searching for something the request  will go to the server and server will fetch the  

all information related to this this particular  keyword and then respond with all the content so   from the client application we are able to browse  the data or we are able to we are requesting the   server to provide some data and the server will  fetch the data related to this keyword and sending  

all this information so this is how exactly  client and server works and the client is not   always a browser uh most of the times we will use  mobile also right in the mobile also we are using   some maps that is also client okay and from where  wherever we are browsing the data through internet  

there all comes under the client application and  where exactly those pages are exist from where   they are exactly operating from there exactly the  software installed that is comes under the server   so this is a basic terminology which we need to  understand what is a client and what is a server  

which is very very important especially when you  are working with the web-based applications now   to understand this more about and we need to also  know something about architecture client server   architecture how exactly this client and servers  will be communicated and what are the different  

type of architectures the web-based applications  will follow and these are basic fundamentals like   we have Wonder our texture two-time architecture  and then we have also a 3D architecture   and web applications mostly followed three  Tire architecture okay web applications will  

follow three-time architecture so let us try  to understand what exactly one tire two tire   and a three Tire so one tire applications one  tire architecture is nothing but what we have a   single system we do not have any internet we have  a single system where the client will be running  

client and there will not be any database actually  there will be some files let's say I'm using   some notepad I'm typing something or I'm typing  something in the MS word or Excel sheet and when   you're saving those files where exactly we are  saving the data in our same machine right in the  

same machine in the file format we are saving the  data and for that we don't need any internet for   that we don't need to maintain any databases right  so these are all one tire architecture so if your   client and the server server here is nothing but  a file system so when you run client and server in  

the same machine which is comes under one tire  architecture so nowadays we do not have such   type of applications because this is pretty old  technology and we will keep the client and server   both in the single system both are running in the  single machine same computer and which is Wonder  

architecture and the two tier architecture means  what we have uh multiple client servers client   computers and they are accessing the database and  this database will be there in some other machine   okay some other machine we will use as a database  server and different client applications will  

access the same database so for example internet  applications suppose if you go to any Bank write   any banking organization so they will internally  maintain their own servers and their staff will   access the database suppose in their organization  let's say 10 to 15 people are working all of  

them are accessing the same database server  which is located in their environment locally   and that is comes under two Tire architecture so  two tire is nothing but what different lines will   able to access single database server and this  database server is a different machine not on the  

same machine so these people let's say 10 people  are accessing these 10 papers don't have their own   local memory so whatever the the tasks they are  doing everything is happen in the common database   and here this is a two-tire architecture when  you come to the three-tier architecture again  

this is divided into three parts and the client  Tire business logic and database layer we can say   this is client application this is a application  server or web server and the database server so we   can divide it into three parts so here client is  nothing but what we are we are all clients we are  

browsing the data from the browser and database  is what actual data will be stored in the database   and between the client and the server between the  client and server there should be some business   logic okay there should be some business logic  is running and what is the responsibility of  

this business logic layer is which will take our  request from the client and same request will send   to the database and fetch the data and again  send back to the business logic layer and same   business logic will again send the response to the  client so this is a indirect process so between  

the client and database there will be one more  layer is there called business logic layer we can   say business lodge which contains a business logic  normally we call ml application server web servers   many things are there so overall we can divide  into three parts so all web applications all web  

applications comes under 3D architecture or follow  the three-terr picture so there are so many client   applications will run business logic layer will be  there and after that database layer will be there   so these are the two different type of machines  located in different locations remote locations  

so as a client we don't actually what is happening  in the back end so what kind of business logic is   executing what kind of database where exactly  our data is stored in so we it is not visible   as a client or as a user I cannot see all of them  but as a client we will able to browse the data we  

will able to send the request to the server and we  will able to get the response from the server but   who is taking the request we say who is processing  it who is sending the response those things are   completely backend they are invisible to the user  so that's how actually web application works so  

again if I divide it into three parts we can call  them as a presentation layer application layer   and data layer we can come we can categorize them  into two sections or two parts one is presentation   layer and then application layer and a data layer  presentation layer is nothing but a user interface  

user interface we are able to access application  through browser right that's called presentation   layer it will present the data which is uh  from server and application layer means what   business Logic the application layer contains a  business logic even web server is also comes in  

this particular middle layer application layer web  server or we can say application server and web   server so these two uh comes under middle layer  and then database layer is a third layer which   is also called as a data layer so presentation  layer application layer and data layer so every  

web application will have three components  or three sections like a presentation layer   application layer and data layer so presentation  layer what is the purpose of presentation layer   here is which will present the data to the user  which is basically called client and what is an  

application layer which is having business logic  and what is the purpose of application layer which   will take the request from the presentation layer  same request again will send to the data layer and   actual data layer contains what which actually  contains the data and whatever the request we  

send corresponding data will be available in the  data layer so application layer will send the same   request to the data layer and the data layer face  the data and again response will be given to the   application layer and this application layer  again send the response to the presentation  

layer so this is how exactly web application  works between presentation layer application   layer and data layer and these three are the  three different components of web application   now to presentation layer normally to develop the  presentation layer web applications or developers  

will use this Technologies like HTML JavaScript  CSS so these are all scripting languages so by   using these cryptic languages the developer  will develop the UI or web applications that   we can see on the browser so the presentation  layer is nothing but a web applications all web  

applications comes under the presentation layer  so these web applications will be developed by   the developers by using HTML JavaScript and CSS  these are scripting languages and applications   are application layer right which contains  a business logic and who will develop the  

business logic again developers will develop the  business logic by using programming languages   like java.net C sharp python C plus plus so  here actual uh programming languages came into   picture so by using programming languages  developers will develop the business logic  

and that business logic is researched inside the  application layer that's the secondary layer now   the third layer data layer which is also called  as a database layer database layer is nothing but   what here we install some databases like MySQL  or it can be Oracle or SQL server or mongodb or  

whatever so many databases are there in the market  and we can use one of the database as a database   layer which is also called Data layer and actual  data is resides inside the database only because   database only can hold the data and application  layer what is the purpose of application layer  

the processing the processing will be taken care  by application what is the processing here again   we'll send the data from the presentation layer we  will request and then application layer will get   the request and same request again sent to data  layer and get the response and same response will  

be presented on the presentation layer so these  three things will internally work for any type of   web applications but as a user what we can access  only in the presentation layer that means we are   able to see the application we are able to work  with the web applications that is all comes under  

presentation layer so application layer data layer  is invisible so we can't directly access them okay   so this is the basic understanding what is client  and server architecture okay so in every tile like   in one tire two tire and Twitter also we will have  a server okay we can have a server but the server  

will be there in the same machine if you go with  the Wonder architecture we can have server in the   same machine and tutor architecture also multiple  machines are there two time means for two term   means at least two components should be there  client is different and server is different here  

database is acting as a server so two different  components two different machines and in the three   interact texture again it is again divided into  three components client is different business   logic is different database is different and  these three will be located in three different  

places and again there will be many number of  clients there will be many number of application   servers there will be many number of database  servers but the overall the architecture level   if you talk we will convert we will categorize  into three different parts client business logic  

which is basically application layer and then  database layer okay presentation application   layer and data so we need to First understand  uh these three things very very important   okay now let us try to understand more details  so what is an API now okay so we understood  

what is presentation layer what is application  layer what is database layer but where exactly   API come into picture so what is an API now let  us try to understand this in detail interface application programming interface so this is the  full form of ABR application programming interface  

so what is the EPA where exactly it  reset and what is the purpose of this API   so the AP is basically used for or communicating  between two applications let's say there are two   different applications and they want to  communicate each other and there should  

be some mediator right there should be some  mediator and that is basically called as an API   so API is a way of communication between two  applications where applications May differ in   their platforms or in terms of technology  so those applications will be developed in  

different platforms and those applications  will be having different functionality but   still we will combine those applications  we can communicate each other by using   API so for example let us take here front-end  applications we have a front-end application here  

so in the front-end application this is basically  a web right so this is basically web application   so this is our web so we discussed three layers  one is for presentation layer so this is called   presentation layer and this is called uh in  middle layer we can say application layer  

or application server or we can say uh web server  in the middle layer and this is called backend   application or we can say data layer or data  database server okay three components so what   what in the web application in the presentation  layer what we will do we will try to access the  

application through UI and we are sending some  requests to the middle layer which is actually   APL layer here actual apis will be reset so API is  nothing but what which contains a business logic   so as we already discussed in the middle  layer we have a business logic inside but  

the business logic is available in the form  of apis the business logic is nothing but an   API so eBay contains a business logic  which is developed by the Developers   so when you're sending the request to the server  or when you're sending the request first it will  

go to the middle layer and what is there in  the middle layer we have different type of apis   so many types of APs are available in the middle  layer and based on our request corresponding API   will be triggered and that APA what that APA will  do again that AP will send the same request to the  

server that is a database layer and fetch the data  here and provide the response to the presentation   and who is send who is taking the request who is  sending the response to us API okay EP is taking   the request and APS itself sending the response  to the presentation layer so that means APA is  

acting as a mediator between presentation layer  and the database layer and where exactly these   apis are present the apis are present inside the  middle layer middle layer which is business logic   which contains a business logic so which will do  two things what is the first thing this is the  

responsibility of the API layer to fetch the data  from the back end and display on the front end   and the other side what is the responsibility  of API this is also the responsibility of the   API layer to take the data from the front end  and insert into the back end so it will take  

the data it will take the request from the  front end again send to the back end and get   the response and provide the same response to  the front enter or presentation layer and this   is a mediator application programming interface  there is a full form actually API application  

programming interface what does that mean which  is basically in application application means what   which contains some functionality and which is  assisting to the application where exactly we are   using application here we are using application  so what API is doing apis is getting the request  

from the application sending response to the  application so it is an application programming   means what which contains a programming logic  and which is also an interface means what it   is acting as a mediator are acting as an interface  between our front end and our backend applications  

so that's the reason the name says API application  programming interface and where exactly these apsr   resides in the middle layer in the middle layer  APS will be available now when you perform the   testing on this particular layer which is comes  under web testing okay we use selenium there here  

and when you directly conduct the testing in this  particular layer which is called as a API testing   so when you conduct the testing in the database  layer which is called as a database testing   three different layers okay and one thing we need  to understand so if you want to test the web or  

web testing if you want to perform through browser  we are able to access the web application so we   are able to see that entire UI and we are able  to interact with the elements and we will able to   perform the web testing but how come we testing  the apis and why we need to test the eaps here  

so if you conduct the testing web right so from  where exactly we are getting the data in the web   application AAP is only providing the data right  through apis we are getting the response on the   UI and what exactly we are validating on the  web applications we are validating the data we  

are validating the functionality on the website  or web testing side right but from where exactly   we're getting the data from where exactly we  are getting this functionality only through   APS we are getting this and if the eaps are not  available our web applications will not work  

because the web application is actually need  the data and functionality which is actually   coming from what middle layer AP is providing  that so we are doing the testing on the website   but what kind of testing we do on here we will do  a pay testing as part of API testing what you will  

do we will instead of testing this web application  we are directly sending the request to the API and   we are getting the response from the API and we  will test the response we will do some validations   on the response same thing is happening the front  end also for example when you're testing the web  

applications we are now testing the here web  so what exactly what you are testing here is   whatever the response uh provided by the API so  because when you send some request through web   application eapas are giving the response and this  response we are testing on the UI so instead of  

testing on the UI what we will do directly we will  access the apis and we will send the request to   the API directly and we'll get the response from  the API directly and we do the testing here so   this is a APA testing so instead of doing testing  on the web we will directly do the testing on the  

apis that comes under the API testing but what is  an advantage so do we get any benefit when you do   the testing on apx yes so what are the benefit we  will get when you test the EPA so normally what   happens is in the real-time environment initially  they will develop the database faster so the day  

first they will ready the database and then they  will develop the apis and then they will develop   the web so these are the three different things  will be developed in three different times by   different people so database developers will  be different API developers will be different  

web developers will be different they are  having different Technologies they should   know different type of Technologies okay now  initially they will develop the databases and   then APS will be developed by the developers  and then web will come into picture so between  

these two there will be lot of time okay first  they will develop all the apis and once the apis   are ready then they develop the web because if  apis are not available there is no use of web   right if they're in yeah they have all everything  is implemented on the UI so login is there images  

there everything links are present everything is  present in the web UI but when you perform some   activity it's not working anything so when you do  login it's not working when you click on the link   it is not working because APS are not yet ready  so without apis if you have only web application  

there is no use so first they have developed the  apis on top of the apis they will develop the web   oh which is they will develop the web application  so web application work based on the apis so the   First Development will happen on the APS and then  the next level development will happen on the  

web based on the apis so as soon as the apis are  ready or developed by the developer if you conduct   testing on apis if you do testing on epas so we  can do less testing on the web because almost   if you come if you complete 80 of the testing  here on the UI side we will just do only 20  

percent of the testing you no need to Do complete  testing so why because the same apis will provide   the response taking a request from the web so  whatever the response or API is giving to the web   right here we will test it but instead of doing  testing here we directly send the request and get  

the response from the API and we do the testing we  do the response validations so here itself we will   finish 70 to 80 percent of the testing and rest of  the testing we will do some basic level testing on   the UI like all the UI elements are alert properly  or not fonts are correct or not colors are  

properly uh put or not so all colors are correctly  mentioned or not so just we do some UI testing   but main functionality testing is done at the  APA level itself because APA itself is providing   the data to the our web application so instead of  testing web application directly we can test the  

EPA functionality that will reduce lot of our  time and that will reduce a lot of our effort   okay so this is a main purpose of doing a pay  testing so this is actually what is an API so   AP is nothing but what application programming  interface why it is an application programming  

interface because which is uh working for  the application and it contains a programming   logic and which is acting as an interface between  presentation layer and the database layer so that   is the reason we can call it as a API application  programming interface and these apis will be used  

to communicate between two different type of  applications let us say this is one type of   application this is another type of application so  these two things will be communicated with the API   okay we can communicate with this and this is the  one way of understanding this okay so yeah we can  

do functional testing in the APA level okay so  in that case in the web web level we no need to   do function testing we will just do the UI testing  okay so if the functional testing is done on the   APA level and the web application what you will  do you will just test the Geo testing graphical  

user interface so all elements are properly  aligned or not alignment existing colors okay   font these things we will just evaluate on  the UI if you conduct functional testing on   the APA level and there is one more thing even  web application is communicating with the AP  

or not so the communication also we need to test  properly right so that's the reason we should also   do some kind of testing on the UI and we should  not really completely on API at the same time we   should not relay complete on the given both are  important both are important to do it but most  

of the testings if we conduct or if we complete on  the APA level we can do less testing on the guis   okay so we can put less effort or less time we  can spend on the GUI testing if you do uh if you   spend more time on the APA testing so that's the  main advantage and moreover we no need to wait for  

the GUI like as soon as the ap's development is  completed you no need to wait for GUI for testing   because it will take some time to develop right  so in the meanwhile itself we will directly test   the EPs and once you get the application or GUI  then you can start testing the GUI and that is  

a process normally we follow so first level of  testing we do on apis level and then next level   once you get an UI and once the UI is developed  then we will conduct the testing on the GUI   so that's how things will happen so because this  will take some time immediately it is not ready  

okay so before that AP should be ready so we will  do most of the testings on API and once the UI is   available then we will do some part of the testing  on the UI both are available both are important   okay so this is how we need to understand what is  exactly AP means and where exactly AP come into  

picture okay so the programming language will be  used to develop the apis application development   will be done by using scripting languages  scripting languages I told in the previous slide   here but just look at here in my previous slide  so presentation layer that's not web application  

will be developed by using HTML JavaScript CSS  so these are the scripting languages will be used   and to develop the apis programming languages will  be used like java.net C sharp python so by using   these programming languages eaps will be designed  or APS will be developed so the languages will be  

different so even developers also different web  developers are different programmers are different   database developers are different okay so everyone  is not having the same kind of a skill set so web   development will be taken gear by some other  people and database layer will be taken care by  

somebody else and abs or business logic will be  developed by some other developers so different   team members different things will be done okay  we should not Club all the Technologies into one   category but overall they will work for the one  goal that is they want to develop an application  

they want to develop a software okay so this  is the basic understanding what exactly client   and server and then we have understood three  tier architecture like front end middle layer   back-end and also we have understood what exactly  AP means and we will try to understand with more  

examples so in this context what is an API API  is an application programming interface which   is contains a business logic and here front end  is one application we can cancel backend is also   another application so these two will communicate  each other through API through API they will  

communicate each other okay so to understand uh  more detail API let's take the simple example   so let us say uh let's take one restaurant  okay to understand what exactly the AP how   it will work so let us take the restaurant  in example so to the restaurant a customer  

come to the restaurant let's say he is called  consumer okay and there will be a waiter also   and uh as a customer what I'll do I'll order for  the food okay so waiter will take the order and   the waiter you will not prepare any food right  so what waiter will do he will go to the kitchen  

and the same request will send to the Chef right  so as a customer I will order the food which is   basically called as a request and waiter will  receive the request and the same request sent   to the kitchen and Chef will prepare the food in  the kitchen so we can consider this is a back end  

so once the kitchen is once the food is  prepared then respond right the waiter   will again provide the food to the customer so  if I just look at these three different things   based on this example we can understand what  exactly APA will do so here he's a client  

he is a client or customer and waiter is acting  as a APA role application programming interface   and Jeff is acting as a database layer so actual  food will be prepared here so as a customer I am   requesting the food to the waiter and what a  waiter is doing same request is again forward  

to the database layer and in the database layer  actually the food will be prepared at the kitchen   and once the food is prepared the same response  will be given to the waiter and this waiter will   provide the food to the customer so here if you  just look at three things are happening so one  

is request from here request is happening  same request will go here again go to the   database and same response we are getting here and  customer will get the food so here this waiter is   acting as a a payroll application programming  interface is a mediator between the customer or  

client and the back Ender so this is he is the  guy he's a communicator between the two things   okay so based on this example we can understand  what exactly AP means how exotic will work   okay now let us try to understand  more so if I just look at this

foreign just a second okay so let's take this  application example let's say make my triple   so make by trip.com so this is a website and  internally this website is using different   type of apis okay so internally this website is  using different type of air base so how exactly  

applications will internally use apis so let us  try to understand so what we understood what is   an API APA means through the APA we will able to  communicate between two applications right so if   I just look at this makemytrip.com so this is an  application so what we can do in this application  

in this application we can find available flights  or we can find available hotels so lot of things   we can find right so as a user right I'm just want  to book a flight ticket so I can provide some data   to this might make my trip okay I can search what  are all files are available by sending some data  

so this is called request okay this is called  request I am sending some information from where   I need to travel from where I should go so on what  date I want to travel so this information I will   provide that's called request and what make my  trip will know how make my trip will work again it  

will get the data from the different airlines like  a different type of aliens we have so each Airline   is different each Airline is having different  flights so how make my trip will get the data   about these Airlines so the same data whatever we  provided same data again they will send to this  

APA so these apis are exposed by these Airlines  different alien companies are having their own   apis so they will expose their own apis so  whatever data we have requested to make my   trip the same data again recent to those apis and  what these APS will do these apis will give some  

response to us and what are the different  flights are available from those Airlines   and these flight information will be again  displayed to the customer so how this make my   trip is getting all the information from different  to Airlines through the different apis and make my  

trip is not developed those apis they are just  using those apis by sending the request and   getting the response and these apis are developed  from whom so these apis are developed by their   own companies their own companies so let me  show you one more example for example every  

day almost everyone we use Google Maps right so  we're using Google Maps so Google Map is an API   so which is developed by so Google is developed  their own apis actually Google is the owner for   all Google related apis Google Maps apis but these  Google Maps we can use in different applications  

so we are using an Uber we are using in WhatsApp  or we are using any other travel applications   but these applications are not exactly developed  with the Google Maps but these applications are   using the Google Maps through the apis through  the apis so Google is the owner for those apis  

Google is owner for those IPS Google is developed  those apis but they APS are exposed to the public   so for example in the WhatsApp you can  share your location to somebody else but   internally location you are sharing means what  Google Maps apis internally uh integrated so  

WhatsApp is basically requesting Google Maps API  to provide the location so that's the integration   but WhatsApp is not developed a Google map or  Google Map apis it cannot locate anything but   it is internally calling Google Maps and Google  Map is providing the directions so like this if  

any companies developed some apis and if they are  exposed to those apis to the public everybody will   able to use those apis everybody else can use  those APS in their applications they don't need   to again develop the same thing so whatever  is already developed and that is available  

through API and other applications will use  it okay for example you have a Google account   you have a Google account so with this Google  account you are able to login into Facebook   you are using the same account to the LinkedIn  you are able to use same account for some other  

thing right so different applications are using  same login purpose but how this Facebook how this   LinkedIn applications will know about your Google  Google account how these applications will know   about this Google account because internally the  Facebook when you're signing up the Facebook when  

I use Google account the Facebook will request  this Google through API and through this API they   will check whether your account is valid or not  if it is valid then they will allow us to log in   similarly when you use Google account to log into  the LinkedIn what LinkedIn will do LinkedIn will  

request to the Google through the API whether  the account is valid or not if it is valid then   API check APA will send the request and get the  response and in the response they will check is   it valid or not then accordingly it will allow  or not they will decide so how these applications  

are interacting with the Google account or  Google because of eapis So based on this we can   understand APA is a tool through API we are able  to communicate between two different applications   Google is a different application Facebook is  a different application LinkedIn is different  

application but we are using same account for  all the applications or not yes we are using   the same account for all applications how these  applications will know about our account through   APA requests they will come to know whether our  login or whether our account is valid or not  

so that's how internally APS work so nowadays  every web application internally use apis   internally use apis so all the functionality  of your application provided only through apis   okay if suppose some functionality is not  working means what some APA is not up and  

running so for example on your application okay  on your application you are trying to access some   functionality okay Suppose there is a some feature  called search and they say you have some feature   on your web application and you are searching  for something here and you are pressing Enter  

key or you are not getting some data here you  are not getting proper results what does it mean   when you're searching for something you requested  something to the server and maybe your APA is down   or your database is down sometimes in those cases  what happened you will not get the proper response  

and your application is not responsible for  that so particular EPA or particular database   is sometimes down in those cases you will not get  proper response so even application functionality   is also works based on eapa request and response  so if you do the testing in the APA level 80 of  

the testing if you do the testing on the API  only rest of the 20 of the testing you can do   on the web application it will reduce a lot of  time and also effort okay so this is a basic   understanding what is an API where exactly  AP come into picture and what we do as part  

of API testing okay let's understand a few more  things so what are the different types of apis   so how many types of apis we have so basically  we have two types of APS in the market   like we have soap you are soap APA soap related  APS and rest apis okay so based nothing but a  

simple object access protocol rest is nothing  but a representational status so these are the   two different type of APs are available in the  market but soap apis are very very old one so very   less number of companies are still using it very  very less and uh most of the companies almost 80  

percent of the companies are using rest Services  nowadays so soap is having their own technology   actually so they internally use XML to process the  data and so on but that is a very old technology   but uh in rest is a latest technology so many  of the companies nowadays are using rest apis  

so soap and rest so these two all two tools uh  these two APS internal use a different type of   technology different type of communications and  different type of data okay so soap support only   XML type of data but rest support XML Json html  text different type of data is also supported  

while you're communicating with the server but  soap support only XML format and this is very uh   XML is very lengthy and that's very complex also  sometimes when you compare with the jsons and uh   it's very weighted data will be sent to the server  so just try to understand these are the two types  

of APs which we have in the market and soap is  very old type of apis and rest is a latest so both   are APA zombie okay but sometimes we use something  called web service so this is a term also normally   we use web service so we need to understand  this also what is API what is web service what  

is the difference okay sometimes we will use  a web service this name is also very popular   okay so what is an API what is a web service see uh when you what is an API we have understood  so far is we basically AP will get the request  

from us and it will give some response to us so  it will take some request it will give you some   response that's a job AP is done right but what  is web service what web service will do thank you   it's very same actually so when you keep this API  in the internet or if it is available on the web  

that is called Web Service simple so Suppose  there is one application okay and there is   another application let's say this is my Google  application and this is my Facebook application   and how these two are communicating each other  through the API and if this API is available  

on the Internet or if this ABA is available on  the web then these two applications will able   to communicate so once you place this API in the  internet that is called as a web service simple   so when you keep this API inside this internet and  everyone able to access that API that is basically  

called as a web service that means what all web  services or EPS only all web services are apis   but all apis are not web services because  until unless we keep this in the internet   we cannot say that as a web service and without  having internet also we can create our apis we can  

test our APS on your local system so internet is  not required for Designing and development or EPs   and testing apis internet is not required okay and  once you conduct the testing and once everything   is working fine then we will move it on the  production environment and we make that available  

that AP is available for the public and that time  we will call them as a web service so web service   and APA technically they are same technically  they are same but once you put this API in the   internet that is called as a web service okay so  at the time of development and testing apis will  

not be there in the production let's say developer  develop some API and uh development is happening   and then testing will happen and while developing  and testing the apis we no need in Internet   okay so they are not available for the  public so far they are developing and  

testing in internally within the company so we  can call them just APS just APS which will take   the request and which will give some response  okay and at the time of development and testing   we call them as a APS even internet is also not  required but once the development and testing is  

completed once the AP is working fine then we  will make this apis available in the internet   because other applications also can use these  apis just like Google Map Google Maps are   designed developed by the Google they have tested  it and after testing what they have done they have  

make available those apis to the public so that  we are able to access it so that is web service   so as soon as this apis developed and tested  once they move to the production and make it   available for the Public Public is able to access  these apis then which is called as a web service  

okay only simple difference a web service  that means what all web services are what apis   but all apis are not web services until unless  we move them into the production until unless we   move them into the internet we can't call  them as a web service it is just an API  

clear everyone the difference between API and web  service so at the time of development and testing   we just call as API we should not say that is a  web service and once it is developed and tested   once they moved into the internet and which is  available for the public to access then we call  

them as a web service once they move into the  web environment which is called as a web service   okay so all web services are basically  apis but not all apis are web service   when when this APA become web service once  they moved into production once they moved  

into the internet once they available  for the public then we can call them as   a web service until then they are  just APS not web services [Music]   so guys is it clear the difference between API  and web service most important interview question

difference between AP and web server  please respond in the chart Window Guys okay now let us see the next one so types of  apis we discussed and also the different types   like APN web service so web service and  API wrapped in HTTP internally they will  

use HTTP protocol and all web services  are API but apis are not web services   remember this point and when APS have become web  service once we move the aps into production or   in web environment once we make available them  to the public then they become the web service  

so a web service needs a network while API  doesn't need any network for its operation   we can test the EPS without internet also  in the locally also we can test the aps   and once they move into the production and web  then we can access the apis through internet  

okay so this is the basic difference between  API and web service now let us try to understand   more about rest apis so we are going to  discuss more on rest apis but not soap apis   okay so what is rest API so rest APA is one of  the type type of the rest API so in the rest API  

basically uh will take the request from the user  or client and we will the same request will send   to the server and server will process the data  phase the data and same response will be given   to the customer so how exactly rest AP works so  rest AP is having different type of methods guys  

okay so rest API methods so these methods normally  we use like we have a get method we have a post   method we have a put method we have a delete  method and there are so many other methods also   there but mainly we will use only four methods  get the post put and delete methods what are  

those methods means they are rest API methods  or we can also call as a request HTTP request   it should be a request see whatever you do on  the web whatever application you are accessing   whatever transaction you're doing all the  transactions all the operations will comes under  

at least one type of request okay for example you  are browsing the google.com Okay so you're opening   the google.com here when you're sending google.com  when you press enter normally what type of request   it will go to the server it will go to server and  get the response so basically it will send a get  

request so what exactly we are doing is we are  trying to get some data from the google.com so   here we are requesting something from the Google  so when you type something here what we are doing   exactly we are requesting something related to  this keyword requesting some data from the Google  

that means we are sending the get request get this  nothing but what it will send some response to us   okay that's called get request this is one of  the requests and then we have a post request   post is nothing but what suppose if you want to  create something in the database server okay if  

you want to create something sometimes you will  create your user you will provide all your first   name last name email phone number everything and  when you submit it what will happen the same data   will be stored in the database but you will not  get any response you are just sending the data  

to the database and that is called as a post  request so get request is nothing but what we   will get the response from the server and post  request is nothing but what we are sending our   data to the server to store okay we are sending  our data to the server which will store that is  

happen through post request suppose I already  have some data in my database on server I want   to update the data I want to edit the data then we  can send a put request so put is another type of   request through which we will able to update  existing data in the database app and delete  

is nothing but what we can delete the data  from the database so for four different type   of operations we will use four different type of  rest API methods get to post put delete so these   four all called HTTP request method so through  browser whatever the request you are sending  

that should comes under either get request or  a post request or put request or delete request   it will comes under one of the requests so rest  API will support these type of request so one is   get request post request put patch delete and so  many other things are there main light categories  

just four types of requests similarly in the  response what the response contains the response   contains some status code data so many things  are there we will do certain valuations on the   response that means we are required we are passing  some requests to the API AP will provide some  

response and then we do some validations on the  response that's how APA testing will be conducted   so first of all we have to know what is the  functionality of API what kind of input we   have to pass to the API and then we will try to  understand what kind of response it should return  

or what kind of response you should provide to the  user and once you know the request and response   then we can test the API so before testing API  you have to know the functionality of the API   the functionality of the API what exactly the  API will do what is the purpose of API why it  

is designed of input it will take what type of  request it will accept what kind of response it   will provide and what is the content which we have  to test in the response so these things we need   to First analyze before it doing APA testing  so in API testing we have mainly four methods  

get to post put and delete and what's the use of  this get if you want to receive some information   from the database right so then we will send  the get request so receive information about   an API resource and similarly create an API if you  want to create something something in the database  

then we will use a post request or if you want  to update anything in the database then we will   use put request or if you want to delete something  in the database then we will use a delete request   so get to post put delete these are the four  different type of requests supported in rest API  

only through request through these  type of requests we will use apis   and we will validate apis and then HTTP and https  and this is another important thing which we   need to understand HTTP is based HTTP and https  hypertext transfer protocol hypertext transfer  

protocols more secure these two are different  type of protocols used by web applications   web applications in essence internally  ABS also will use these protocols   to communicate between their client and the server  so what is the difference between HTTP and https  

https is a more secure communication will happen  suppose when you're sending the data through the   client application to the server your data will  be transferred as it is in the original format   so if your data is passing through the network in  the original format there is a chance of hacking  

the data so they are not more secure but if your  web application is using https and that data is   more secure so when you're sending some request or  data which will be converted into encrypted format   and throughout the network the data will be  transported through encrypted format and then it  

will reaches to the server again their deprecation  will happen and process will happen so basically   the data is communicating or data is transforming  through the network in the encrypted format   and that is more secure sometimes when you're  browsing some web pages also you can see his  

sleepy and his deepest protocol so you can see  HTTP is nothing but water okay here you can see   so you can just copy this so you can just ping  any website it will show you some HTTP or https see here let me just type something and say  google.com I'm opening so this is the page  

I'm opening you can see here this is a page I  have opened now if I just look at this before   starting the URL you can see something here and if  you see htl DPS needs nothing but that website is   more secure okay the data will be sending through  encrypted format but if some website you can see  

only HTTP that means what the data is sending in  the original format they are not secure websites   okay so you need to understand this what  is the difference between HTTP and https   and now we need to understand few important  terminologies before going to API testing  

like you are a URL and URL Ura is nothing  but a uniform resource identifier URL is   nothing but uniform resource locator  urns uniform resource name so where   exactly these come into picture so we need to  understand about the URL let us take this URL  

so https colon slash slash google.com articles  article there is some URL is there so we   can call this completely as one URL uniform  resource locator uniform resource locator this   completely we can call them as URL or Ura uniform  resource identifier or uniform resource locator  

but again which contains multiple parts so here  HTTP or https which is called as a protocol or we   can call them as a scheme and this part is a host  google.com or something amazon.com flipkart.com   so that's basically host or we can also call  as a domain where exactly our data is present  

and rest of this is called as a path so  here HTTP or https is called as a protocol   and this part is called a host or domain and rest  of the part is called path so in this particular   domain or in this particular host or in this  particular server where exactly our data is  

present so in the Articles folder in the article  name this is called actually resource which is   actually called as a resource in a web application  when you ping any URL this is complete URL   so this is one part and this is another part this  is another part so actually which one will faces  

the data in the server only this one will fetch  the data so first it will go to the Articles and   then it will go to article name and wherever the  data is here this will be and this data will be   returned from the server okay and this is a path  so what is urn means what uniform resource name  

actually what is the actual resource here this  is the actual resource what is the resource here   resource this is a technical term resource  is something which is available in the server   for what we are requesting resource is something  which is there in the server which we can request  

so when you send some request to the API what  API will do AP will send the same request to the   server and in the server whatever we requested  that information is there or not and this is   called as a resource so whatever we are requesting  for that information is available in the server  

right so that is called as a resource so whenever  you are sending some request it will try to fetch   the resource and that resource information is also  available in this URL this is called resource this   is called resource name uniform resource  name you are in we can call them as a URL  

okay so what is an end point what is an end point  and this is another Point end point end point is   nothing but this part again this path entire  thing is comes under the end point other than   this host other than the host okay so other than  this host whatever the rest of thing is there that  

is called N Point okay that's called end point  okay so other than here till here we are Host   this is server actual data will be stored and from  this rest of thing whatever is there that's called   end point and end point is also include path  URL and then uh resource okay resources also  

this is actually a resource and this is a path  and both combinedly we can call as a endpoint   okay so the terminology is most  important which we need to understand   and next one uh resource and normally  in the web application testing we call  

it as a feature right feature is nothing but  water is a functionality it is a term used in   manual testing to test some functionality and  similar similarly resource is the term used in   AP automation testing referring some functionality  resource is nothing but something is there in the  

server and we are able to access it that's called  a resource and then next terminology is a payload   because these terminal loss is most important  while performing API testing is okay you have   to learn you have to understand this payload  what is payload payload is nothing but the data  

which we are sending along with the request  and also the data which is coming along with   the response both are called payload request  payload and response period suppose let us   say I have a flight booking application okay so  let's say I have one flight booking application  

and in the flight booking application I will  provide my data right I will provide my name   right and source and destination place and date I  will provide some data when you booking a flight   so we we are with this particular data  and this is called as a request payload  

this is called as a request payload and once you  send this we will get some response Right Flight   is booked or not with confirmation and a Time  availability all the information we will get   as a response and that is called as a response  payload response payload means what the payload  

is nothing but a data payload is nothing but a  data and the data which is sending through request   which is called as a request payload the data  which is coming through response which is called   as a response payload okay we use these terms very  very frequently in API testing please listen this  

and the next one is here you can just look at this  picture to understand more so let us say consumer   and producer consumer is nothing but what whoever  is sending the requester they are all consumers or   we can call them as a client and when you send  a request and these are the different things we  

will pass like you are a headers a payload and  this payload can be in Json format or XML format   we can pass and once the server is received that  request EP is received the request and sent to the   database and corresponding HTTP method will be  done like it can be posed get put or delete and  

we'll get the response again when you're getting  the response we will also get some data along with   the response and that is called response payload  like status code and some response data some   string a message you will get something out of  the response and that is called response payload

okay so this is important thing and then so  a few more important things so whenever you   perform APA testing what we're getting API URL  or endpoint so you need both okay URL is nothing   but a complete path okay the complete thing is  called url url is nothing but what the complete  

URL you are requesting right this is complete  thing is called URL what is an end point this   part is called end point this part is called end  point so when you're performing the API testing   you will get all these end points from the  developer okay and where exactly the data  

is hosted and based on that this will  be change the hostname can be changed   okay suppose the apis are deployed in some  machine some X then the hostname will be X   and if the apis are deployed in y in some other  server then this hostname will be different  

but the end points will not be changed the  endpoints will not be changed so when you do   APA testing we have to know the end points which  are provided by the developers and also they will   provide the location where exactly the apas are  deployed accordingly this URL will be changed  

and when you're sending the request when you're  sending the get request or post request we will   have to send this complete URL along with the  end point we have to Center only end point is   not enough when you're sending the real request  to the API but at the time of writing the test  

cases and getting the information developer so  they will provide only the end points and then   we will use these endpoints along with the host  and that will make completely appear request   okay so this is a basic understanding now I'm  going to show you few simple and very sample apis  

how exactly these apis will work and there are so  many websites are there they will provide so many   types of apis and we can do some kind of testing  on those apis so Ura and URL are the different on   same both are same so you are a some people are  called Ura uniform resource identifier and some  

people are called uniform resource locator okay  so the terminology is used by different people   in the different purposes you can consider the  entire thing as a URI URL or some people will   consider only some part is called Ura so some  people will consider only this part is Ura so  

that's the reason I put both the points so this  part is called as a Ura some people will consider   and some people will consider the entire thing as  a URI except this protocol remove this protocol   rest of them is considered as a URI okay so the  terminology you have to just understand theatrical  

differences not important but you need to just  understand mainly URL and then uh end point as   I said end point right end point is different  URL or Ura you can consider as the same and end   point is most important because URL Ura can be  changed but the end point will not be changed  

okay so guys are you clear so far everyone so  this is the basic understanding what exactly   API how exactly AP works and what API will do  and what's the purpose of an API okay I will   show you now few important apis few sample apis  and then we will try to understand few things  

and let's go to Google Just a second okay  so here we have a sample API just a second and request response dot in so this is provided  some sample apis just for practicing purpose and   we will do so many other EPS also so just  for your understanding I'm just going to  

show you a few number of apis here so you can  just look at this these are different type of   apis they have provided here okay so these  are the different apis they have provided   and you can just look at this get there  are so many gets are there post put patch  

delete right different type of requests  are there and you can just look at this   this is a request and this is a response okay  suppose the first TP what's the purpose of the   first EP here is list users okay listy users when  you send this request it will list out all the  

users which are available in the database I'm  just clicking on the get here see this I'm just   clicking on the getter as soon as you're clicking  on the get what happens this is a request actually   sent to the server okay this is a request which  is actually sent to the server and this is a  

response we got 200 is a response we got and  this is a response data in the Json formatter   okay so most of the times we use Json as a request  and response in the next sessions I will discuss   more about Json so these are response data so  uh user's email ID user first name last name  

Avatar so this is this is the information we got  it from the server when you send the get requester   okay this is called payload yes and the same  request we can directly send so for example this   is a host actually okay this is the host see  here so this is a host okay and what is a end  

point this is the end point this is the end point  so this is the end point let me just copy this okay so this is the end point let me copy and  just I'm adding the end point to the URL here okay   and this is a complete URL guys okay now if you  send this request directly browser like this you  

can also get the response now we can see this  is the response but here they have given inbuilt   options here to send a get request put request  post requests and so on and whenever you click   on this button corresponder request will go and  we will get the response so whatever response you  

captured here the same response we also captured  here same response okay this is how we need to   send the a b request this is a get request so  there's a reason we got the data and similarly let   me send one more suppose I want to get the single  user data from the database so I'm sending the get

so you don't need to confuse anything guys for  now you can just consider URL URI is the same   okay no confusion you can consider  as a shape URL URI is the same okay   no confusion that's not much important actually  okay so when you click on the get request this  

time second one I'm getting the data of the single  user single user data I got now this time what is   the request it is an API slash user Slash 2 and  this is now we got the response to 200 200 is   nothing but what successful request if the request  is successfully done then you will get the 200.  

and we also have different response codes like  200 201 401 501 different type of responses codes   we have based on that we can decide whether  the request is successfully completed or not   so now with the same request I want to test  through my browser how we can test again same  

host I can put here first okay same host and  what is the end point to get the single user   what is the end point to get the single user  this is the end point APA slash users slash   to apa slash users slash two so I can say APA  slash users slash two so when I say two here  

I'll get the information about the second user  so let me just copy and send that in the browser   so even through browser also we can send the  request and we can get the response from the   API but everything is not possible through browser  only get three is possible get request is possible  

through browser but when you do Post request or  delete request or put request through browser it   is not possible okay we have to use different  tools like Postman so here only get request   is possible through browser so I'm sending the  complete URL here then I got the information of  

the single user so when it says send to here I  got the id2 here so I got the user information   second user information suppose I want to get  the third user information I can say three here   then I got the third user information okay so I'm  sending some request and then I got some response  

from the eapi that is also get request now let  us see one more type of request so let us say   this is single user not found and here this is  also get request list of resources and single   resources and post requester create means what it  will go and create a new user in the database for  

that we will use post request and suppose the  user is already available now I want to update   then I can use put requester and Patch is also  for updater and delete request suppose user is   already there then I want to delete the user then  I can send a delete request so different purposes  

we can send different type of request but only  through browser get requests are possible post   request put request delete request these  things are not possible through browser   we have to use some other tools so that's the  reason we cannot use here okay payload is nothing  

but a the data which we will send through the  requester okay payload is nothing but the data   which will send through request and will get some  data from the response also right that's a payload   for example I'm sending the get request here are  you sending any payload along with this request  

guys please respond are we sending any  payload with this requester payload are   we sending any payload to this request no we are  not sending any payloader but uh once you send   this request are we getting some response  here yes we are getting some response data  

right this is called payloader response payload  response payload sometimes you will send post   the post request here click on the poster  when you're sending the post request okay we   have to send some data also what is the use of  post request which will create a new record in  

the database which will create a new record in  the server and what is the details of that new   record we have to pass like if we pass a name and  a job accordingly it will create a new record in   the database so this is called request payload  along with this request URL we should also send  

some data this is called as a request payload and  this is a response payload once you requested to   create this data it is created exactly this  time and it is also given some response to us   okay so payload is nothing but a data request  payload is nothing but what the data which is  

sending through request along with the request  which is called as a request payload the data   which is getting from the response which  is called as a response payload simple   okay so these are all sample  apis they have given and uh  

and the host is already here so we're just given  some end points here and we can just export this   API directly here when you click on this get  here and when you send this resource now I   got some response here this is also get request  and suppose when you send it post request click  

on post here and now this name and job is sent  through this request and we got some response here   with the same name and job and with the uh some  created it suppose I want to delete some request   so then go to the delete here and now here we  need to pass some delete which one is deleted

we pass to we will not get any response data here  because the data is got deleted the record is got   deleted the response is what two zero four is a  response so some type of request we have to send   payload and some type of request we don't need  to send any payload so 2 0 is 4 is nothing but  

a no content yes that record the second record is  not there in the database so it is giving some no   content because these are all some dumb dummy  APS they may not take proper data they may not   give proper records or proper response and from  tomorrow I will show you the different type of  

APs which are real apis exactly we are going  to test okay and these are some dummy AP just   for your understanding I'm just showing you these  apis a different type of request and get request   we can also send through browser also but post  request put request delete request these type of  

requests we cannot send so you need to understand  one important thing guys whenever you test an API   okay whenever you test an API we have to pass some  request we have to pass some input let us take any   API we need to pass some request and we will get  some response and as part of the request what you  

will pass you will pass the data and you will pass  the URL sometimes you will pass some keys some   class sometimes you will pass some authenticated  information lot of things we have to send two   requests sometimes but every APA may not require  everything but sometimes we have to pass something  

regarding this along with the request and whenever  you get some response we will get some response   data we will get some response status code and  we will get some cookies we will get some headers   response so many things we will get as part of the  response so we need to validate all the stuff and  

that is part of your API testing so as a job as an  APA tester job what is our responsibility we have   to know what kind of request we have to send to  the API we have to know what kind of response it   should return and accordingly we have to test  the response we do a lot of variations on the  

response and that is what APA testing means that's  what API testing means later the Apes testing is   completed then this AP is integrated with the  web application now this Webby application will   interact with the API now whatever transactions  will do this web the everything will happen  

through APA so basically whatever the operations  we'll do on the web these operations will go   to AP in the form of request and the API will  return the response uh APA will return the data   to the web in the form of responsor so instead of  testing this web if you directly test this API by  

sending request and response our API testing job  is done so this is what exactly API testing means   so guys understood now there are so many apas  are exposed from different type of companies   like we have Google Maps API we have uh Facebook  apis and also we have LinkedIn apis so git GitHub  

apis so there are many types of apis some of them  are freely we can access some of them or require   some authentication information and some of them  we cannot directly access because they are more   sensitive epas the companies they will use their  internally purpose so all payment Gateway is also  

APS so when you do some kind of payment it will  show you different payment options like you pay   payment net banking credit card debit card right  there internally having their own apis so when you   select the internet banking option it will trigger  some type of API and when you use payment option  

is UPI then that will trigger another type of API  right everything is happen only through apis but   as a user we cannot see those apis internally once  it is integrated but at the time of testing we are   able to access the apis which are developed by  the developers and then we are able to test them  

okay so this is all about introduction part like  what is an API testing what is client server or   Texture and uh what is exactly API testing means  what how API Works what are the different type of   requests right so these things we have understood  as part of indirect sensation in the next session  

we will try to install Postman tool and  then we will start manual testing of apis   okay so that's the plan so is it clear  everyone on today's session so I'll   stop here for today's session and if you  have any general things we will discuss