Flutter is created by Google as a framework for development of Android and iOS mobile (and desktop) applications with the same code-base (GitHub repository, install Flutter). It lets using Material Design and Cupertino (iOS-flavor) widgets with native performance. Flutter is free and open source, it is already used by Google, Alibaba and other companies and developers.
Dart is an Open Source programming language (GitHub repository), created by Google. It is used in some of Google applications (e.g. AdWords). Google also created:
- SDK – includs the VM, dart2js, core libraries, and more
- Flutter – for mobile application development
- AngularDart – for web application development
- Dart tools – IDE plugins, server script tools, and more