Can you name the main abstract concepts and components used in Flutter for creating interfaces?

In Flutter, the following core abstract concepts and components are used to create interfaces:

• Widget — the basic building block of the interface. Everything in Flutter is a widget: buttons, text, containers, even the app structure.
• StatelessWidget — a widget without state that does not change after being built.
• StatefulWidget — a widget with state that can change during the app's runtime.
• BuildContext — an object that provides information about the widget's location in the widget tree.
• Element — the link between a widget and the render object, managing the widget's lifecycle.
• RenderObject — responsible for rendering and positioning elements on the screen.

Example of a simple StatefulWidget:

class MyCounter extends StatefulWidget {
  @override
  _MyCounterState createState() => _MyCounterState();
}

class _MyCounterState extends State<MyCounter> {
  int _count = 0;

  void _increment() {
    setState(() {
      _count++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        Text('Count: \\$_count'),
        ElevatedButton(onPressed: _increment, child: Text('Increment')),
      ],
    );
  }
}