What are Widgets?

In Flutter, a widget is the building block that represents your UI. A button, a line of text, some padding, a layout, even an entire screen — they're all widgets. Instead of thinking of a widget as an object, think of it as an instruction card describing what should appear on screen. A Flutter app is structured as a widget tree. A parent widget holds a child widget, and that child widget can hold further children of its own. Understanding this tree will help you pick up layout, styling, and state updates much faster.

Scaffold(
  appBar: AppBar(
    title: const Text('Widget Tree'),
  ),
  body: const Center(
    child: Text('Every UI piece is a widget'),
  ),
)

A screen with an app bar appears, and in the middle of the body you'll see the text "Every UI piece is a widget".