Introduction to Node.js - JavaScript Framework

6/29/2025
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javascript framwork Node.js logo with a server architecture diagram showing request handling

Introduction to Node.js - JavaScript Framework

Introduction to Node.js - JavaScript Framework

Node.js is an open-source, cross-platform JavaScript runtime environment that allows developers to run JavaScript code outside of a web browser. Built on Chrome's V8 JavaScript engine, Node.js is designed to build scalable and fast network applications, especially web servers and APIs.

Note: Although commonly referred to as a "JavaScript framework," Node.js is technically a runtime environment, not a framework.

Key Features of Node.js

  • Non-blocking I/O: Uses asynchronous event-driven architecture for high performance.

  • Single-threaded: Handles multiple requests with a single-threaded model using event loops.

  • Cross-platform: Runs on Windows, macOS, and Linux.

  • NPM (Node Package Manager): Huge ecosystem of open-source libraries and modules.

  • Built-in modules: Core modules like http, fs, path, etc., for fast development.

Why Use Node.js?

  • Ideal for building RESTful APIs, real-time applications, and microservices

  • Full-stack JavaScript development (same language on frontend and backend)

  • High performance for handling concurrent connections

  • Strong community and corporate support (e.g., from OpenJS Foundation)

Common Use Cases

  • Web servers and APIs

  • Real-time chat applications (e.g., using Socket.io)

  • Streaming services

  • Command-line tools

  • Server-side rendering with frameworks like Next.js

Simple Node.js Server Example

const http = require('http');

const server = http.createServer((req, res) => {
  res.statusCode = 200;
  res.setHeader('Content-Type', 'text/plain');
  res.end('Hello from Node.js server!');
});

server.listen(3000, () => {
  console.log('Server running at http://localhost:3000/');
});

Popular Frameworks Built on Node.js

  • Express.js – Minimalist web framework

  • NestJS – TypeScript-based full-featured framework

  • Koa.js – Lightweight and modern web framework

  • Socket.io – For real-time communication

Conclusion

Node.js revolutionized server-side development by allowing developers to use JavaScript for backend programming. With its non-blocking architecture, robust package ecosystem, and flexibility, Node.js is an excellent choice for building scalable and efficient server-side applications.

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