1. What is JavaScript? The Web's Dynamic Heart

JavaScript is a powerful, high-level, interpreted programming language primarily used to create interactive and dynamic content on web pages. Alongside HTML (structure) and CSS (presentation), JavaScript is the third core technology of the World Wide Web. It runs directly in the user's web browser, without needing to communicate with a server for every interaction.

If HTML is the **blueprint** and CSS is the **decorator**, JavaScript is the **behavioral layer**. It's what makes your website respond to user actions (like clicks, hovers, form submissions), perform calculations, fetch data in the background, animate elemen