# What is JavaScript? — JavaScript Fundamentals: From Syntax to Async

Source: https://www.skillbyai.com/en/javascript/js-intro

> Learn what JavaScript is, where it runs from browsers to servers, and how it adds behaviour to HTML and CSS.

## 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.