The difference between API and REST API

What is an API?

A way to let software components to talk to each other, and it could be in any form.

How do APIs relate to Web Services?

• Web Servieces are just APIs, but in general, not the other way around.
• REST API = REST web service

REST API/REST Web Service?

An API that follows the rules of REST specification.

• How software components will talk?
• What kind of messages they will send to each other?
• How requests and responses will be handled?

What’s REST?

REpresentational State Transfer

How does HTTP relate to REST?

• HTTP is an application layer protocol for sending and receiving messages over a network.
• In HTTP, we can use GET method for all sorts of interations.
• REST is a specification that dictates how distributed systems on the web should communicate.
• REST is a certain way to implement and use the HTTP communication.

How does The WEB relate to REST?

• REST is the underlying architecture of the WEB.
• Some developers are breaking the rules.
• It’s not the best architectual style but it’s still better than doing things arbitrarily.

The most popular REST rules

1. The method information should be expressed in the HTTP verb.

   // Not RESTful
   GET api/users/delete/:userId
   
   // RESTful
   DELETE api/users/:userId

2. Scoping information should go in the URI.

   DELETE api/users/:userId <-- URI

How a RESTful API works?

• It uses proper HTTP methods according to the situation (GET for getting data, POST for creating data)
• Scoping info(and other data) goes in the parameters part of the URI.
• It uses common data formats(most commonly JSON).
• Communication is stateless.

Source

https://www.youtube.com/watch?v=FOZtRzY5x8E