Dart is a programming language developed by Google that is designed for building web, server, and mobile applications. It is known for its ease of use, strong performance, and support for modern programming concepts like asynchronous programming and object-oriented design. Dart can be compiled to native code or JavaScript, making it versatile for various platforms. One of the most popular uses of Dart is in the development of Flutter, a UI toolkit also created by Google. Flutter allows developers to create natively compiled applications for mobile, web, and desktop from a single codebase, leveraging Dart's capabilities for efficient and responsive app development.