to properly answer this question
drifting, in regards to its most popular usage, refers to inducing a RWD car into a slide scenario by using several different techniques (weight shift, ebrake, power over, etc or combinations of those).
Once the car becomes sideways there is a skilled usage of the throttle, brakes, clutch, and ebrake to continue the slide and exit the slide cleanly. it is a combination of all driving skills, and is much harder than it appears.
to put it shortly, it is an exhibition of driver skill. one must have skill before one can exhibit it. learn the basics of performance driving (vehicle weight transfer, racing lines through turns, and smooth brake and throttle usage) before attempting it.
next time there is a drift event, feel free to ask myself or any of the ants for a ride if your curious.