Coexistence is a device to make communication between people in a long distance relationship feel more natural. Coexistence helps communication by making it feel like you are carrying out a conversation in the same room. It has a motion sensor so it knows when walk in room and starts the call. Unlike a phone call there isn't pressure to speak the entire time you leave it on when you're in the room and you talk whenever you feel like it. if you're in the middle of a conversation and have to go to another room you can pick it up and bring it with you.