Flutter is an open-source mobile application development framework created by Google. It is used to develop applications for Android, iOS, Windows, Mac, Linux, Google Fuchsia, and the web from a single codebase. Flutter uses Dart as the programming language and offers a rich set of widgets and tools that makes building apps a breeze.
For example, the Flutter framework provides a wide range of widgets for creating user interfaces. These widgets include Material Design, Cupertino (iOS-style widgets), and other widgets that can be used to create beautiful, custom UIs. Additionally, Flutter also provides a rich set of APIs for accessing device features such as camera, location, storage, and more.