In Flutter, both functions and classes can be used to create reusable widgets, but they have different purposes and use cases.
Functions are used to create simple, stateless widgets that only display information and do not change over time. For example, you can use a function to create a widget that displays an image and some text, but does not change the image or the text in response to user interaction. Functions are typically simpler and easier to read and maintain than classes, but they are not suitable for creating complex or dynamic widgets.
Classes, on the other hand, are used to create stateful or dynamic widgets that can change over time in response to user interaction or other events. For example, you can use a class to create a widget that allows users to select an item from a list, or to create a widget that displays a countdown timer. Classes are more powerful and flexible than functions, but they are also more complex and harder to understand and maintain.
In summary, you should use functions to create simple, stateless widgets and classes to create more complex, stateful or dynamic widgets. The choice between functions and classes depends on the complexity and behavior of the widget that you want to create.