Specifically what i mean is, in most bikes, are they assisted braking either by vacuum, or other means? Or does the hydraulic pressure come strictly from your hand pulling the lever. 

Just to clarify, i know HOW disk brakes work. The reason i'm asking is because i know that there are other front ends out there that will match up directly to a T500 that have Disk brakes. i'm just trying to figure out what parts i would need, or if there is anything i should take into consideration as far as parts in case of serious comparability issues. It would suck to buy a fork and triple tree set up to find that the brakes won't work because i need to hook vacuum lines to the engine somehow (which is a doubtful scenario, but, you never know). 

#disk brakes