What is West Coast Swing?

from WikiPedia:

West Coast Swing is a partner dance with roots in the Lindy Hop. It is characterized by an elastic look that results from its extension-compression technique of partner connection and is danced primarily in a slotted area on the dance floor. 

The dance allows for both partners to improvise steps while dancing together, putting West Coast Swing in a short list of dances that emphasize improvisation.

Typically the follower walks into new patterns traveling forward on counts "1" and "2" of each basic pattern, rather than rocking back. Traditional figures include 6-count and 8-count patterns of one of the four basic varieties: (1) Starter Step, (2) Side Pass, (3) Push Break / Sugar Push, (4) Whip.

Alternatively, the basic patterns in West Coast Swing are defined as: Sugar Push; Left Side Pass; Right Side Pass; Tuck Turn; and Whip. Virtually all other moves in West Coast Swing are variations of these basic patterns. The Anchor Step is a common ending pattern of most West Coast Swing figures.