Introduction to Node.js — Official Learn Guide

Node's official Learn section used to be thin. It isn't any more — the OpenJS Foundation has built it out into a properly structured guide, and the page our link points at is the first stop: what Node is, why running V8 outside the browser matters, what non-blocking I/O buys you, and a Hello World HTTP server you can run in about a minute.

That single page is short. The value is what surrounds it in the sidebar, which is a genuine curriculum covering most of what a working Node developer needs.

What the wider guide covers

• Getting started — JavaScript prerequisites, how Node differs from the browser, the V8 engine, npm, ES6 and beyond, debugging, WebSockets, security, and dev versus production
• Command line — running scripts, the REPL, input and output, environment variables
• HTTP — the anatomy of an HTTP transaction
• Files — stats, paths, reading, writing, descriptors, folders
• Asynchronous work — callbacks, promises, timers, blocking versus non-blocking, and the event loop, process.nextTick and setImmediate
• Modern Node — TypeScript, the built-in test runner, mocking, code coverage, streams, Node-API
• Diagnostics — memory, performance, flame graphs

What it assumes and doesn't say

The guide expects JavaScript. It says so, links out, and then proceeds. What it doesn't do is teach you to build anything — there's no project, no application, no worked example that grows across pages. Each article is self-contained, which makes it excellent for looking things up and poor for learning in sequence. You can read the entire asynchronous section and still not know how to structure a server.

Who it's for

Front-end developers moving to the back end who want authoritative answers rather than a blog post from 2019. The event loop, streams and diagnostics material is genuinely hard to find explained this well for free. Skip it if you want to build an API — you want Express's guide or a project-based course. Skip it too if you've never written JavaScript; nothing here will slow down for you.

Our take

The most reliable Node material there is, and it reads like documentation because that's what it is. The honest weakness is that our listing treats a single introduction page as a course with a duration attached, when the actual thing worth your time is the twenty-odd sections behind it. Bookmark the Learn index rather than this page, work through the asynchronous and modules sections properly, and get your project structure from somewhere with an opinion.