Bhattacharyya distance

Bhattacharyya distance is a way of measuring how different two things are from each other. It is like a number that shows how close or how far away two things are from each other. It's a bit like standing at one end of a room and looking across to the other end: the bigger the room, the further away you are from the other side. Bhattacharyya distance is a way of measuring the size of that room.