What is JavaScript?

JavaScript is a versatile, high-level programming language primarily used for enhancing the interactivity and functionality of websites. Initially created to run in the browser, JavaScript can now run on servers as well using environments like Node.js. It’s an essential part of the web development trifecta: HTML for structure, CSS for styling, and JavaScript for behavior.

JavaScript is:

• Interpreted: Executes line-by-line in the browser.
• Dynamically typed: No need to declare variable types.
• Prototype-based: Uses prototypes instead of classical classes (though ES6+ includes class syntax).
• Event-driven: Built to handle user actions like clicks and keypresses.

It is supported by all modern web browsers and is the backbone of interactive and dynamic content online.