SnackBar & ScaffoldMessenger

SnackBar is a widget that displays a message at the bottom of the screen for a short period of time and then disappears. It's often used to display confirmation messages or error messages to users.

ScaffoldMessenger is a widget that provides access to a set of functions that allow you to display SnackBars, BottomSheets, and other types of messages from anywhere in your app.

Together, these widgets make it easy to display messages to users in response to user actions or other events.

For example, you might use them together to display a SnackBar when a user submits a form, using the ScaffoldMessenger to show the SnackBar:

ScaffoldMessenger.of(context).showSnackBar(
  SnackBar(content: Text('Form submitted')),
);

This would display a SnackBar with the message "Form submitted" at the bottom of the screen.