The minimal Flutter app simply calls the runApp() function with a widget: import 'package:flutter/material.dart'; void main() { runApp( const Center( child: Text( 'Hello, world!', textDirection: TextDirection.ltr, ), ), ); } The runApp() function takes the given Widget and makes it the root of the widget tree. In this example, the widget tree consists of two widgets, the Center widget and its chil