From Wikipedia, the free encyclopedia: Twerking is a type of dancing in which the dancer, usually a woman, shakes her hips in an up-and-down bouncing motion, causing the dancer's buttocks to shake, "wobble" and "jiggle".[1] According to the Oxford Dictionary Online, to twerk is "to dance to popular music in a sexually provocative manner involving thrusting hip movements and a low, squatting stance".[2] The word twerking is of uncertain origin. Possibilities include a contraction of "footwork", or a portmanteau of twist and jerk.

UM, it's something easier to see than to have explained. Maybe search YouTube, or Google, just make sure you have safe search on, LOL