Here are some ways

‣

Core Data

UserDefaults

Property List File

When to save data

1. Data is changed
2. Data collection is changed
   1. Add
   2. Remove
   3. Update
3. The app is suspended

@Environment(\\.scenePhase) var scenePhase

yourview.onChange(of: scenePhase, perform: { newValue in
                if newValue == .inactive {
                    card.save()
                }
            })