Class Positions

Ok simple question. In Xp whats the difference between a battler in the front, middle, or back position? I can't seem to figure it out.

Ok simple question. In Xp whats the difference between a battler in the front, middle, or back position? I can't seem to figure it out.

Wow, I acutally never noticed it said that.

EDIT: I think though it has something to do with defense and maybe attack because on the default shields it says like good for front and then good for middle, and then good for back.

I have no knowledge of RMXP whatsoever, but at a guess I would say it's how much physical damage they do/take.
Generally with battle positions, at the front you do AND receive more physical damage and the back is the other way around (you do and receive less physical damage).
Magic and ranged attacks stay the same, I think...
This is probably just a wrong, wild guess though.