Lesson 1 / 38

What is JavaScript?

What JS is, and where it runs.

A language for the web

JavaScript is a high-level, dynamically-typed scripting language created by Brendan Eich in 1995. It's the only language browsers run natively.

Where JS runs

Originally browser-only, JS now runs on servers (Node.js), mobile apps (React Native), and even desktop apps (Electron).

JS vs HTML/CSS

If HTML is a page's skeleton and CSS its appearance, JavaScript is the behavior — it makes the page react and change.