For more information, see Layouts.

Using Material Components

Flutter provides a number of widgets that help you build apps
that follow Material Design. A Material app starts with the
MaterialApp widget, which builds a number of useful widgets
at the root of your app, including a Navigator,
which manages a stack of widgets identified by strings,
also known as “routes”. The Navigator lets you transition smoothly
between screens of your application. Using the MaterialApp
widget is entirely optional but a good practice.

Now that the code has switched from MyAppBar and MyScaffold to the
AppBar and Scaffold widgets, and from material.dart,
the app is starting to look a bit more Material.
For example, the app bar has a shadow and the title text inherits the
correct styling automatically. A floating action button is also added.

Scaffold widget takes a number of different widgets as
named arguments, each of which are placed in the