Flutter is a UI toolkit launched by Google for developing cross-platform web, mobile, and desktop applications using a single codebase. Initially, Flutter was launched with support for Android and iOS, but in March 2017, Flutter 2 was introduced to support Linux, Windows, macOS, and other operating systems. Flutter runs with Dart, an object-oriented programming language also developed by Google.
With Flutter, developers need to write the code once, which can be deployed for multiple platforms. So, that same code will work for iOS, Android, desktop, web, and other embedded apps.