Locking is the first professional street dance. Don "Campbellock" Campbell invented lockin' in the late '60's when he was trying to do the funky chicken. He couldn't do it, but in the process he stumbled upon this style.
Locking is hard to explain without showing, but has many moves: Uncle Same points, knee drops, and playing with the hat, to name a few. (Also, within the style of locking, there is a move called locking.)
To many, locking is a way of life in which every gesture or facial expression one makes is exaggerated.
All information obtained from The Freshest Kids.