It's all about context. The idea is to have beacons placed far from each other and have them properly calibrated. iBeacon devices can have its broadcast power adjusted to levels that allow your app or receiver device to know more precisely which beacon is closer or further. If you have two beacon transmitters placed side by side in a small room and working at full broadcast power, only magic will help your app to know which one is the closest or which one is the furthest - imagine a room with a few people talking. If all of them talk very loudly, you won’t be able to listen to what each of them are saying, but if each person whisper, you’ll be able to listen to each one as you get close to them. Does it make sense?