REST stands for Representational State Transfer. By definition, it is an architectural principle of the Web. In practice, it is a set of rules that simplify client-server communication. A lot of companies provide REST APIs because they are simple and highly scalable.

To better understand what REST exactly means, let's take a simple example. We have an online store and we want to manage the users in our system. We have the backend logic implemented in various controllers. We want to trigger functionalities there via HTTP requests. In other words, we need an application program interface for these controllers. We start by planning the URLs to access our server. If we follow the REST architecture, then we may have the following routes: