Understanding the widget tree

Flutter describes UI as a tree of widgets. A widget is an immutable configuration; State objects hold mutable state for StatefulWidget.

BuildContext

BuildContext identifies a widget location in the tree. It is used to access inherited data such as Theme, MediaQuery and Provider. Avoid retaining a context longer than the widget lifecycle requires.

class Greeting extends StatelessWidget {
  const Greeting({super.key});

  @override
  Widget build(BuildContext context) {
    return Text(
      'Welcome',
      style: Theme.of(context).textTheme.headlineSmall,
    );
  }
}