What is state management in Flutter and why is it important?

State management refers to how an app handles, shares, and responds to changes in data across its widget tree. In simple apps, setState() within a single widget is sufficient. But as apps grow, data needs to be shared between multiple screens and widgets. Poor state management leads to deeply nested callbacks, duplicated data, and hard-to-debug UI bugs. Flutter has several approaches ranging from simple (Provider) to powerful (Riverpod, BLoC) — choosing the right one depends on your app's complexity.