Node.js is mainly used for server-side programming in web development. 

Traditionally, JavaScript was primarily used on the client side to enhance the interactivity and user experience of websites, but with Node.js, JavaScript can also be used on the server side to handle various backend tasks. If you are a student of web design courses in Delhi and want to master JS then you should also get the idea of Node.js.

Here are some key use cases of Node.js in web development:

1. Building Web Servers: Node.js is well-suited for creating web servers that handle incoming HTTP requests and serve responses. Developers can use the built-in "http" module to create custom web servers and define how the server should respond to different requests.
2. Single-Page Applications (SPAs): Node.js can be used to serve static assets for single-page applications (SPAs). It can serve the HTML, CSS, and JavaScript files needed for the frontend, and it can also handle API requests and other backend tasks required by the SPA.
3. Microservices Architecture: Node.js is well-suited for building microservices, which are small, independent components of a larger application. Its lightweight and event-driven nature make it a good choice for creating individual microservices that can be easily scaled and maintained.
4. Proxy Servers: Node.js can be used to create proxy servers that manage requests and responses between clients and other servers.
5. Web Sockets and WebRTC: Node.js supports WebSockets, which enable real-time two-way communication between clients and servers. This is useful for applications that require constant data exchange, such as instant messaging platforms and live streaming apps. Node.js can also be used in conjunction with WebRTC to build peer-to-peer communication applications.

In summary, Node.js is mainly used in web development for creating server-side applications, APIs, real-time applications, microservices, and other backend services that power modern web applications. 

Start you training with the professional nodejs programs at ADMEC: