Express.js Mastery / Express Welcome

Let's Install Node.js

⚙️ What Node.js Actually Is

  • Node.js is a JavaScript runtime — it lets you run JS outside the browser.

  • Before Node, JavaScript could only run inside a browser (Chrome, Firefox, etc.).

  • Node uses Google's V8 engine (the same one that powers Chrome) to execute JavaScript on your machine/server.

  • This is what makes backend development with JavaScript possible.

💾 Download & Install — More Context

Two version tracks on nodejs.org:

Track

Meaning

Who it's for

🟢 LTS (Long-Term Support)

Stable, tested, receives security updates for a long time

Most users, production apps

🆕 Current

Latest features, but less stable

Developers who want to try new features early

Version numbering rule:

  • ✅ Even numbers (10, 12, 14, 16...) → stable, safe for production.

  • 🧪 Odd numbers (9, 11, 13...) → experimental/transitional releases.

  • 🔄 This is Node's own release convention — odd versions eventually get replaced by the next even LTS.

Why version doesn't matter too much here:

  • 🛠️ Core Node.js fundamentals (modules, event loop, require/import, async patterns) stay consistent across versions.

  • ➕ Minor syntax/API additions happen, but breaking changes are rare between LTS versions.

  • 🔙 If code breaks on a newer version, switching to the LTS version used in a course is a safe fallback.

📥 Installation Process

  1. 🌐 Visit nodejs.org

  2. 🤖 The site auto-detects your OS and shows a download button.

  3. 📂 If not auto-detected → go to the Downloads page → pick your OS manually.

  4. ▶️ Run the installer:

    • 🍎 Mac: .pkg file → Continue → Agree → Install.

    • 🪟 Windows: .msi file → Next → Agree → Install.

  5. 📦 The installer also installs npm (Node Package Manager) automatically — this is used later to install libraries like Express and Mongoose.

✅ Verifying Installation in Command Prompt/PowerShell/Terminal

node -v

Prints the installed Node.js version (confirms the installation was successful).

Also useful to check npm:

npm -v

Confirms npm (which comes bundled with Node.js) is installed and working correctly.

🍃 MongoDB Note

  • Node.js installs the same way on all operating systems.

  • MongoDB installation is OS-specific (different steps for Mac vs Windows) — covered separately later.