Well I'm sure you looking for more information than the above answers....the rut? Well unlike the above answers and although we are primarily hunting bucks, the rut has all but nothing to do with the bucks other than, they need to be there....like us men.
The rut is defined as the period of time when the does in a given area come into estrous for breeding purposes or you could say the rut is the whitetails breeding season. Peak rut would be defined when the majority of does in the given area are in estrous (heat) for the first time and pre-rut is the period of time leading up to peak rut. Does in an area come into estrous at different periods depending on when they were born, in other words, age. And obviously, post rut is the period of time after peak rut when most of the does have been bred however their might be a few still in estrous or coming into estrous. If a doe is not bred during this time frame, she will again come into estrous approx 28 days later and possibly a third time...therefore there can be a second or third rut stage.
Estrous? When a doe is "in season", "heat" and is accepting bucks for breeding.
Too many people see bucks chasing, sparing, etc and assume it's the rut however one has to remember that the bucks are ready to go, all but year around and the "rut" is only taking place when the does are ready. The does control the rut, the rut is all about the does and nothing about the bucks.
Many define it tho because at this time of the year as light fades the bucks also go through transformations preparing for the does "rut". Bucks antlers harden, velvet falls off, buck begin to rub trees to strengthen their necks, and start creating scrapes. The bachelor group of bucks who tolerated each other might now begin to fight for dominance and pecking order....it's all part of "rut" rituals but remember, if the does don't come into estrous, it's all for nothing so again, the bucks only have to be there and the "rut" is all about the does.
Bucks might run around trying to get lucky with the ladies but if the does are not in estrous, it's not the rut.
Hope that elaborates it a little more than....it's heaven.