Don't forget to explain that some buttons are inside faint pill shaped shading (or it could be a search field in which they could tap without consequence) and that chips (to show options for a specific context, so they could tap without consequence) are rounded rectangles.

Except if the site is still on Material Design 2, then it is the reverse in which some buttons are inside rounded rectangles and that chips are inside pill shaped shading.

Are we confused yet?