REST stands for Representational State Transfer, and it’s a style of architecture for crafting network applications.
REST API design, in simple terms, means writing code which allows you to use other software as a “black box” – meaning that you can integrate important functionalities into your own project in an easy way, and without having to integrate the whole application with your own system.
It is very commonly used in web development. Developers don’t need to install new software, or use any libraries to take advantage of a REST API.
It was first defined in the year 2000, and it has proven very useful thanks to the incredible flexibility that it provides to developers.
In a sense, a REST API makes it possible to “call” another system, and ask it for the data that your system needs.