In Flutter, a stateful widget is a widget that has mutable state. This means that the widget's state can change during the lifetime of the widget. A stateful widget is useful when the widget's state depends on some user input or other dynamic factors.
On the other hand, a stateless widget is a widget that does not have mutable state. This means that the widget's appearance does not depend on any changing factors, and the widget can be rebuilt with new data without affecting its state.
Here are some guidelines for deciding whether to use a stateful or stateless widget:
If the widget's state depends on user input or other dynamic factors, use a stateful widget. For example, if the widget displays a form that the user can fill out and submit, use a stateful widget to manage the form's state.
If the widget's appearance does not depend on any changing factors, use a stateless widget. For example, if the widget displays a static image, use a stateless widget.
If the widget's state changes frequently, consider using a stateful widget to avoid rebuilding the widget too often.
If the widget's state does not change, or only changes infrequently, use a stateless widget to avoid the overhead of managing a stateful widget.
Ultimately, the decision to use a stateful or stateless widget depends on the requirements of your specific use case.