In Node.js, modules are the building blocks of your application — they help you organize your code into reusable chunks.

📦 What is a Module in Node.js?

A module is simply a file in Node.js.

• Every .js file is its own module.

• Modules can export functionality (functions, variables, objects).

• Other files can import that functionality using require() or import.

🧱 3 Types of Modules

✅ Local Module Example

1. math.js — your own module

js
const math = require('./math');console.log(math.add(5, 3)); // Output: 8

🌐 Core Module Example

js
const path = require('path');const filePath = path.join(__dirname, 'test.txt');console.log(filePath);

🧙‍♂️ How Exporting Works

You can export a function, object, class, or anything else:

js
// file: greet.jsmodule.exports = function(name) {  return `Hello, ${name}`;};

js
// file: app.jsconst greet = require('./greet');console.log(greet('Alice')); // Hello, Alice

🧪 ES6 Modules (import/export)

If you're using "type": "module" in package.json, you can use ES6 syntax:

js
// math.jsexport function add(a, b) {  return a + b;}// app.jsimport { add } from './math.js';console.log(add(2, 3));

📚 Common Core Modules