JavaScript is a high-level, interpreted programming language that conforms to the ECMAScript specification. It is widely used in web development to create interactive and dynamic websites. JavaScript can be used to manipulate HTML, CSS, and the Document Object Model (DOM) to create rich user interfaces and responsive web applications. It supports event-driven programming, asynchronous programming, and functional programming paradigms, making it versatile and powerful. JavaScript is supported by all modern web browsers and can also be used on the server-side with platforms like Node.js. It has a large ecosystem of libraries, frameworks, and tools, such as React, Angular, and Vue.js, that simplify web development and enhance productivity. JavaScript is used by millions of developers worldwide to build a wide range of applications, from simple websites to complex enterprise applications.