Why Learn JavaScript?

Three practical reasons JavaScript is usually one of the first languages people learn:

• It's the only language browsers run natively — if you want a web page to respond to clicks, validate a form, or update without reloading, it's done in JavaScript.
• One language, both ends — Node.js lets the same language run the server too, so a single skill set covers a full web application.
• Huge ecosystem — npm (Node's package manager) hosts more published packages than any other language's package registry.

See What Can You Build With JavaScript? below for concrete examples.