Node JS Learning

Day 1

Learnt the first page of original documentation of node.js .

Day 2

Learning the first module or code example or server or api example.

Day 3

We have learnt 2 new pages of Node.js Documentation and come to know that there are following differences in node and browser Node.js

Node.js vs Browser JavaScript – Key Differences

Both environments run JavaScript (same language, same V8 engine in most cases), but the runtime, APIs, purpose and constraints are very different.

#	Feature / Aspect	Node.js (Server-side)	Browser (Client-side)
1	Execution Environment	Server / local machine / container	Web browser (Chrome, Firefox, Safari, etc.)
2	Main Purpose	Backend, APIs, CLI tools, scripts, servers	Frontend UI, DOM manipulation, user interaction
3	Global Object	global	window (also self, globalThis)
4	DOM / Window / Document	Not available	Available (core part of the platform)
5	File System Access	Yes (fs, path, streams, etc.)	No (except very limited File System Access API)
6	Direct Network / Server	Yes (TCP, UDP, HTTP/HTTPS server, WebSockets, etc.)	Restricted (mostly fetch, WebSocket, no raw TCP)
7	Module System (2025–2026)	Both CommonJS (require) and ESM (import)	Mostly ESM (import / <script type="module">)
8	Package Management	npm / pnpm / yarn / bun — full control	CDN, bundlers (Vite, esbuild, webpack), import maps
9	Environment Control	You decide version & OS	You don't control user's browser/version
10	Security Model	Full system access (dangerous if not careful)	Strong sandbox + same-origin policy + permissions
11	Standard Web APIs	Missing most (no fetch until recent versions, no localStorage, no alert, no setTimeout polyfill needed)	Full set: fetch, localStorage, IndexedDB, Canvas, WebRTC, Web Workers, etc.
12	Performance Characteristics	Single-threaded event loop + worker threads	Single-threaded event loop + Web Workers
13	Typical I/O Handling	Non-blocking I/O optimized for thousands of connections	Event-driven, mostly user & network events
14	console.log destination	Terminal / log files / systemd	Browser DevTools console
15	process / OS information	Yes (process.env, process.argv, os, cpu, etc.)	Very limited / none
16	Best For (2025–2026)	REST/GraphQL APIs, real-time (Socket.io), SSR, tools, scripts, microservices	Interactive UIs, SPAs, PWAs, games, visualizations

V8 JavaScript Engine

• V8 is the JavaScript engine i.e. it parses and executes JavaScript code.

Other JavaScript Engines

• Firefox has SpiderMonkey
• Safari -> JavaScriptCore(Nitro)
• Edge -> Chakra(old), Now -> Chromium + V8

Day 6

I made a first project file manager cli. It is an automation script that can read files list files and give data.