Wondering what an API is and how to document it is a thought every Analyst comes across at least once in their career journey. With a plethora of APIs on the market, it becomes difficult to keep track of what to learn and what to leave, but before it all, we must understand what an API is and how it works/helps.

API stands for Application Program Interface. In easier words, it’s a set of definitions and protocols for building and integrating application software. It works as an interface between two programs or systems. In easier words, an API is software that establishes a connection between two applications. This is why, when companies or organizations want to make some data available for the public at large to pull, they make it through the APIs.

As shown in this diagram, there is a lot of communication going in between databases, web servers, APIs, and web applications. But how exactly is it working?

If the web application wants to access some data from another application or any of its functionality, they request the data using the APIs working in the background as a middleman for both applications.

For Example, when we try to check the news update on our phone, we use an API to access the data by hitting the web server of that specific site or application and in return, access their database, which will return the desired results by fetching the data from the database.

In computing terms, the request is sent from the application to the API using the internet, the API communicates with the web server and the database and then, fetches the data we requested. This is why, just as Newton explained in his third law, a response is expected when the request is sent.

Now, you must be thinking if every time developers need to create new APIs altogether. Well, the answer ranges from No to Maybe.

With the digitization in trend, businesses don’t actually create new APIs primarily, rather they use the already generated APIs by other companies in their projects for time and cost efficiency.

In case, the required API with the desired business logic for the web application under development is not available in the market (which happens once in a blue moon), the businesses come up with newly defined or updated APIs. Also, in most cases, once the API is built, it is made available to the public at large which helps organizations all around the globe in cutting their developmental costs.