juniorFlutter
Explain the concept of Widgets in Flutter.
Updated Apr 28, 2026
Short answer
In Flutter, everything is a widget. Widgets are immutable descriptions of part of a user interface.
Deep explanation
Widgets form a tree structure. They represent structural elements (like buttons or text), stylistic elements (like padding or fonts), and even layout aspects (like rows and columns). When the state changes, Flutter builds a new widget tree and compares it to the old one to determine minimal rendering updates.
Real-world example
Constructing a complex login screen by composing smaller widgets like TextFields, Buttons, and Paddings together.
Common mistakes
- Thinking of widgets as mutable views (like Android Views or iOS UIViews). Widgets are lightweight and immutable configurations.
Follow-up questions
- What is the Element Tree?
- What are layout widgets?