How to use Column Widget

Widget that displays children vertically.

To fill the available vertical space, wrap the child widget with Expanded widget. Column does not scroll. If you need a scrolling list, consider using ListView.

How to use AppBar Widget

Widget to implement the material design app bar. The app bar consists of a toolbar and possibly other widgets such as TabBar and FlexibleSpaceBar.

AppBar class(API reference)

Toolbar

Implementation example of leading, title, and actions.