Sliver
How to Slivers Work?
Widgets that we frequently use inside a Scaffold extend the abstract class RenderConstrainedBox. For example, Container, ListView, Text, etc. extend the abstract class RenderConstrainedBox
But we cannot use slivers directly in Scaffold. We will have to add a CustomScrollView which can hold an array of slivers. And these slivers extend the abstract class RenderSliver.
In Flutter CustomScrollView is a type of scrollView which has a property named slivers. This can hold an array of widgets that extend the abstract class RenderSliver.
These widgets have some capabilities beyond those of simple widgets (widgets which extend RenderConstrainedBox) such as expanding and shrinking the app bar, control over the scroll effect, a widget with scrolling effect.