Express.js

Meet Express.js

Express.js is a lightweight web framework for Node.js that helps developers build APIs and the server side of web applications. Routes connect URL paths and HTTP methods to functions that handle requests and send responses. Middleware runs between those steps, making it possible to organize request processing, add logging, parse incoming data, and handle errors in reusable pieces.

The framework includes support for serving static files and parsing JSON or form submissions. Additional middleware can extend an application with features such as cookie handling, while routers group related endpoints into separate modules. Developers install Express through npm and can start with a small JavaScript server, adding libraries and project structure as their application needs grow.