"An API is a contract between your server and everyone who wants to talk to it. REST is the language that contract is written in."
Introduction
Every time your frontend fetches a list of users, a mobile app submits a form, or one service talks to another — that communication happens through an API. And the most widely adopted style for building those APIs is REST.
REST isn't a library or a framework. It's a set of conventions — a shared language for structuring how clients and servers communicate. Express.js is the tool that makes implementing those conventions in Node.js clean and fast.
By the end of this guide you'll understand what REST means, how HTTP methods map to actions, how to name your routes correctly, and how to build a complete set of user endpoints with Express.
