Introduction to API - Most Widely asked Interview Question | Lecture 2

𝐖𝐡𝐚𝐭 𝐢𝐬 𝐀𝐏𝐈: Application Programming Interface?
An API is set of 𝐫𝐮𝐥𝐞𝐬 𝐚𝐧𝐝 𝐬𝐩𝐞𝐜𝐢𝐟𝐢𝐜𝐚𝐭𝐢𝐨𝐧𝐬 that allows one application to leverage services/functionality/data of other application.
When 𝐨𝐧𝐞 𝐚𝐩𝐩𝐥𝐢𝐜𝐚𝐭𝐢𝐨𝐧 (the client) wants to use the 𝐜𝐚𝐩𝐚𝐛𝐢𝐥𝐢𝐭𝐢𝐞𝐬 provided by another 𝐚𝐩𝐩𝐥𝐢𝐜𝐚𝐭𝐢𝐨𝐧 (𝐭𝐡𝐞 𝐬𝐞𝐫𝐯𝐢𝐜𝐞), it makes a request via the service's 𝐀𝐏𝐈.
The API defines how this request should be made, what data should be included, and the format of the response that the client can expect to receive.
𝐋𝐞𝐭 𝐮𝐬 𝐝𝐞𝐜𝐨𝐝𝐞 𝐦𝐞𝐚𝐧𝐢𝐧𝐠 𝐨𝐟 𝐀𝐩𝐩𝐥𝐢𝐜𝐚𝐭𝐢𝐨𝐧 𝐏𝐫𝐨𝐠𝐫𝐚𝐦𝐦𝐢𝐧𝐠 𝐈𝐧𝐭𝐞𝐫𝐟𝐚𝐜𝐞
Here 𝐀𝐩𝐩𝐥𝐢𝐜𝐚𝐭𝐢𝐨𝐧 means both the application 𝐂𝐥𝐢𝐞𝐧𝐭 and 𝐒𝐞𝐫𝐯𝐞𝐫, 𝐏𝐫𝐨𝐠𝐫𝐚𝐦𝐦𝐢𝐧𝐠 means both are 𝐩𝐫𝐨𝐠𝐫𝐚𝐦𝐦𝐞𝐝 in such a way that they can talk to each other
𝐈𝐧𝐭𝐞𝐫𝐟𝐚𝐜𝐞 because it is the medium of communication between 𝐂𝐥𝐢𝐞𝐧𝐭 and 𝐒𝐞𝐫𝐯𝐞𝐫
𝐓𝐲𝐩𝐞𝐬 𝐨𝐟 𝐀𝐏𝐈𝐬:
𝟏. 𝐖𝐞𝐛 𝐀𝐏𝐈𝐬: Apis that allows user to communicate over web . Also known as Web Services . Example: Rest, SOAP, GraphQL etc.
2. 𝐎𝐩𝐞𝐧 𝐀𝐏𝐈𝐬 (𝐏𝐮𝐛𝐥𝐢𝐜): publicly available APIs. Like Google Map
𝟑. 𝐈𝐧𝐭𝐞𝐫𝐧𝐚𝐥 𝐀𝐏𝐈𝐬 (𝐏𝐫𝐢𝐯𝐚𝐭𝐞): not publicly available and are designed for internal use. Ex: Internal API for managing Employee data
𝟒. 𝐋𝐢𝐛𝐫𝐚𝐫𝐲 𝐁𝐚𝐬𝐞𝐝 𝐀𝐏𝐈𝐬: Selenium & Rest Assured. Selenium allows to talk to Web Browser while RestAssured allows to talk to Rest APIs
𝐃𝐁 𝐀𝐏𝐈𝐬: to interact with DB Systems. Ex: JDBC
𝐇𝐚𝐫𝐝𝐰𝐚𝐫𝐞 𝐀𝐏𝐈𝐬: APIs to interact with hardware devices Ex: Camera, mic, speaker etc.
𝐂𝐥𝐨𝐮𝐝 𝐀𝐏𝐈𝐬: Cloud APIs provided by cloud service providers in order to be consumed by developers. Ex: AWS, Azure, Google Cloud APIs
𝐏𝐚𝐲𝐦𝐞𝐧𝐭 𝐀𝐏𝐈𝐬: Allows developers to integrate payment processing capabilities in to the system. Ex: Paypal, Razor pay
𝐖𝐞𝐛𝐒𝐞𝐫𝐯𝐢𝐜𝐞𝐬 𝐯𝐬 𝐀𝐏𝐈: important Interview Question
API: Broder term which includes all APIs
WebService: subset of API and is a service available over the HTTP protocol
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Regards
PrinceAutomationDestination

[@karthickrajpattabi]

Detailed content. kudos for your hard effort

[@PrinceAutomationDestination]

Thanks Karthik ☺️

[@igwe6547]

Thank you for a clear explanation of API

[@PrinceAutomationDestination]

Welcome

[@rateebhatt83]

hello Prince .. very nice explanation.. could you plz increase the volume a little

[@PrinceAutomationDestination]

Looks good to me, could you please cross check and confirm
Anyway i will increase the volume in upcoming videos

[@sushantbhakare5867]

here we have to use kafka as messaging queue to produce and consume the message.

[@PrinceAutomationDestination]

Great