Flutter development involves building cross-platform mobile applications using the Flutter framework, which is developed by Google. Flutter allows developers to create natively compiled applications for mobile, web, and desktop from a single codebase. It uses the Dart programming language and provides a rich set of pre-designed widgets and tools to build visually attractive and high-performance apps. With Flutter, developers can achieve a native look and feel on both Android and iOS platforms without the need for separate codebases.