Express.js

Express.js is a minimal and flexible web application framework for Node.js that provides a robust set of features for building web and mobile applications. It simplifies the process of creating a server-side application with JavaScript by offering powerful tools for handling routing, middleware, HTTP requests, and more.

Key Features of Express.js:

1. Routing: Express makes it easy to define routes to handle HTTP requests (GET, POST, PUT, DELETE, etc.).
2. Middleware: Middleware functions in Express help handle requests and responses, allowing for tasks like request parsing, authentication, error handling, and more.
3. Templating Engines: Express can easily integrate with various templating engines like Pug, EJS, and Handlebars to generate dynamic HTML content.
4. Simple to Use: With a few lines of code, we can create a server and handle HTTP requests.
5. Flexible and Extensible: Its modular structure allows us to add only the functionality we need, and we can extend it with various third-party libraries.
6. Error Handling: It offers built-in support for handling errors and improving application stability.

Common Use Cases:

• Building APIs and RESTful services.
• Serving static files (like images, HTML, CSS).
• Handling form submissions.
• Integrating databases (e.g., MongoDB, MySQL) to create full-stack applications.

Express is one of the most widely used frameworks in Node.js development due to its ease of use and scalability.