What Exactly is Node.js?
Node.js is a powerful JavaScript runtime built on Chrome’s V8 JavaScript engine. Unlike traditional JavaScript that runs in browsers, Node.js allows JavaScript to run on servers, making it possible to build complete web applications using just one programming language.
Key Features:
- Event-driven architecture
- Non-blocking I/O model
- Lightweight and efficient
- Cross-platform compatibility
- Huge ecosystem (npm)
Why Developers Love It:
- Uses JavaScript everywhere
- Fast execution
- Great for real-time apps
- Active community
- Perfect for microservices
How Node.js Works
Traditional web servers create new threads for each request, which consumes memory and eventually maxes out. Node.js operates on a single thread using non-blocking I/O calls, supporting tens of thousands of concurrent connections.
// Simple Node.js example
const http = require('http');
const server = http.createServer((req, res) => {
res.statusCode = 200;
res.setHeader('Content-Type', 'text/plain');
res.end('Hello World from Node.js!\n');
});
server.listen(3000, () => {
console.log('Server running at http://localhost:3000/');
});Node.js vs Traditional Servers
| Feature | Node.js | Traditional (Apache, etc.) |
|---|---|---|
| Processing Model | Event-driven, non-blocking | Thread-based |
| Concurrency | Handles thousands of connections | Limited by threads |
| Best For | Real-time, I/O heavy apps | CPU-intensive operations |
Common Use Cases
Node.js shines in several application types:
- Chat applications – Real-time capabilities
- APIs – Fast and scalable backend services
- Microservices – Lightweight services architecture
- Data streaming – Processing data as it comes
- Tools & Utilities – Build scripts and dev tools
Next: Setting Up Node.js Environment →