What is API ? APIs have become the center of software development, Complete Guide to APIs

APIs have become the center of software development, connecting and transferring data to millions of applications every day.

the guide covers simple explanations of all basic concepts of APIs as well as the most common HTTP status code and, more importantly, a list of popular APIs that you can use to improve you applications.

What is API ?

API stands for

Application Programming Interface.

It's a connection between computers or between computer programs. It is a type of software interface, offering a service to other pieces of software.

Basically, it enables apps to exchange data and functionality and securely.

It let your product or service communicate with other products or services without having to know how they're implemented.

A great example to understand API

imagine you're sitting at a table in a restaurant with a menu of choice to order from. The kitchen is the part of the "system" that will prepare your order.

what is missing is the critical link to communicate your order to the kitchen and deliver your food back to your table.

That's where the waiter or API comes in. The waiter is the messenger - or API -- that takes your request or order and tells the kitchen--the system--what to do. Then the waiter delivers the response back to you; in this case it is the food.

How an API works ?

APIs sit between an application and the web server, acting as an intermediary layer that processes data transfer between systems.

01. A client application initiates an API call to retrieve information also known as a request.

This request is processed from an app to the web server via the API's Uniform Resource Identifier (URL) and includes a request verb, headers, and sometimes a request body.

02. After receiving a valid request, the API makes a call to the external program or web server.

03. The server sends a response to the API with the requested information.

04. The API transfers the data to the initial requesting application.

While the data transfer will differ depending on the web service being used, this process of request and response all happens through an API.

Whereas a user interface is designed for use by humans, APIs are designed for use by a computer or application.