My favorite example of this: a MacBook's headphone socket has full support for iPhone earbuds. The little headset microphone is used and the volume/pause button

My favorite example of this: a MacBook's headphone socket has full support for iPhone earbuds. The little headset microphone is used and the volume/pause buttons operate exactly as on an iPhone. Obvious in retrospect, but just another example of how Apple treats their product range as a complete ecosystem.