What is JavaScript? JavaScript (JS) is the programming language of the web browser. HTML provides structure, CSS style, and JavaScript behaviour: reacting to clicks, validating forms, updating content without reloading, animations, games. It also runs on servers (Node.js), but in this module we use it in the browser. JavaScript is not the same as Java.
Features: interpreted (runs directly in the browser, no compile step), dynamically typed (variables can hold any type), event-driven, and supports object-oriented and functional styles. The language standard is called ECMAScript (we use modern ES6+ syntax).