What is Tai Chi?

Tai Chi (also written as T'ai Chi, Taiji, Tai Chi Chuan, among others) is a slow-motion, moving meditative exercise for relaxation, health and self-defense. Originally from China, Tai Chi has gained enormous popularity in America and throughout the rest of the world for its health benefits.
What is Push Hands (or Sensing Hands)?

Push hands, also sometimes called sensing hands, is a middle skill. It is self correction for your form, and a bridge between the Tai Chi form and Tai Chi as self-defense.