Node.js is a JavaScript runtime built on Chrome's V8 engine that allows you to run JavaScript on the server. It uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, ideal for data-intensive real-time applications.
Node.js comes with npm (Node Package Manager), the world's largest software registry.
// Install Node.js from https://nodejs.org
// Check version:
node --version
npm --version
// Run a script:
node server.js
// server.js — basic HTTP server
const http = require('http');
const server = http.createServer((req, res) => {
res.writeHead(200, { 'Content-Type': 'text/html' });
if (req.url === '/') {
res.end('<h1>Hello from Node.js!</h1>');
} else if (req.url === '/about') {
res.end('<h1>About page</h1>');
} else {
res.writeHead(404);
res.end('<h1>404 Not Found</h1>');
}
});
server.listen(3000, () => {
console.log('Server running at http://localhost:3000');
});