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JavaScript Full Course

⭐ Lv 1

Lesson 1/138

Lesson 1.1 — What is JavaScript

Theory: The Behavior Layer

A web page is built from three layers, and JavaScript is the one that brings it to life:

  • HTML — the structure and content
  • CSS — the look and style
  • JavaScript — the behavior and interactivity

With JavaScript you can respond to clicks, update the page without reloading, do calculations, and talk to servers.

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script.js
Console

// console output appears here — hit Run