Express.js is a fast, minimalist web framework for Node.js that simplifies building web applications and APIs. It provides robust routing, middleware support, and flexibility while maintaining high performance.

Features of Express.js:

• Lightweight and fast framework for building web applications.
• Middleware support for handling requests, responses, and authentication.
• Flexible routing system for creating APIs and web services.
• Full compatibility with Node.js and npm packages.
• Supports templating engines like Pug, EJS, and Handlebars.

To check the installed Express.js version, use:

npm list express

Disclaimer: Express.js is an open-source web framework for Node.js, maintained by the Node.js community. It is provided under the MIT License and is not affiliated with, endorsed by, or sponsored by any commercial entity. This information is for educational purposes only. Express.js is provided "as is," without any warranty, express or implied. Users utilize this software at their own risk.