Flash cards
Review the key moves
1/4
Core idea
What is the main idea behind Node.js vs Browser?
Lesson checks
Practice each idea before moving on
Short Mimo-style checks built from this lesson's code, terms, and sequence.
1Quick choice
Which statement best captures the main point of this lesson?
2Fill blank
Complete the missing token from the example code.
___.mylet = 42;Key Differences
Node.js and browsers both run JavaScript, but they have different environments and capabilities.
Node.js is designed for server-side development, while browsers are for client-side applications.
- APIs: Node.js provides APIs for file system, networking, and OS, which browsers do not. Browsers provide DOM, fetch, and UI APIs not available in Node.js.
- Global Objects: Node.js uses global ; browsers use window or self .
- Modules: Node.js uses CommonJS ( require ) and ES modules ( import ); browsers use ES modules or plain <script> tags.
- Security: Browsers run in a sandbox with limited access; Node.js has full access to the file system and network.
- Event Loop: Both environments use an event loop, but Node.js has additional APIs for timers, process, etc.
- Environment Variables: Node.js can access environment variables ( process.env ); browsers cannot.
- Package Management: Node.js uses npm/yarn; browsers use CDNs or bundlers.
This page explains the key differences, with examples for each environment.
Global Objects
// Node.js
global.mylet = 42;
console.log(global.mylet); // 42// Browser
window.mylet = 42;
console.log(window.mylet); // 42File Access
// Node.js
const fs = require('fs');
fs.readFile('myfile.txt', 'utf8', (err, data) => {
if (err) throw err;
console.log(data);
});// Browser
// Not allowed for security reasonsHTTP Requests
// Node.js
const https = require('https');
https.get('https://example.com', res => {
let data = '';
res.on('data', chunk => data += chunk);
res.on('end', () => console.log(data));
});// Browser
fetch('https://example.com')
.then(response => response.text())
.then(console.log);Modules
// Node.js (CommonJS)
const fs = require('fs');// Node.js & Browser (ES Modules)
// import fs from 'fs'; // Node.js only, not browser
// import _ from 'https://cdn.jsdelivr.net/npm/lodash-es/lodash.js'; // BrowserComparison Table
| Feature | Node.js | Browser |
|---|---|---|
| File System Access | Yes | No |
| Networking (TCP/UDP) | Yes | No |
| DOM Access | No | Yes |
| Global Object | global | window/self |
| Modules | CommonJS/ESM | ESM/Scripts |
| Environment Variables | Yes ( process.env ) | No |
| Security | Full OS access | Sandboxed |
| Package Management | npm/yarn | CDN/Bundler |