1. by animation a Shape
2. animation via their ViewModifiers

protocol ViewModifier {
   typealias Content // the type of the View passed to body(content:)
   func body(content: Content) -> some View {
      return some View that almost certainly contains the View 
   }
}

Important takeaways about Animation

Only changes can be animated. Changes to what?

1. ViewModifier arguments
2. Shapes
3. The “existence” (or not) of a View in the UI
   (the comings and goings of Views)

Anmation is showing the user changes that have already happened (i.e. the recent past).