Frame works quite similar to a Rectangle, but with a few exceptions. For example, it automatically nests, so if you draw a Frame on top of another Frame, it will try to group them together. You can still manually group a selection, but this is done by wrapping your selection in another Frame. If you’re a developer, you can consider Frames to be elements. They can have smart layout constraints, relative sizing, and positioning, and can be converted to Stacks or Grids.