What is JavaScript?

• JavaScript is a programming language used to make web pages interactive.

• HTML builds the content, CSS designs it, and JavaScript brings it to life.

• If a website reacts, moves, shows messages, validates forms, or updates without reloading, that’s JavaScript doing the work.

Example:
Html:

<p id="msg">Original Text</p>
<button onclick="changeText()">Change</button>

JavaScript:

function changeText() {
    document.getElementById("msg").innerText = "Text changed!";
}

Advantages:

- Runs Directly in the Browser
No installation, no setup. Every browser already supports JavaScript.

- Makes Websites Interactive
Animations, form validation, sliders, popups, menus — all powered by JS.

- Fast Execution
Runs immediately in the user’s browser, so no waiting for server responses for every small action.

- Huge Ecosystem
React, Vue, Angular, Node.js — JavaScript has massive libraries and frameworks for building anything.

- Works on Both Frontend and Backend
With Node.js, you can build servers, APIs, and full apps using just JavaScript.