Taiji (tai chi) is an internal Chinese martial art practiced for both its defense training, its health benefits and meditation. The term taiji refers to a philosophy of the forces of yin and yang, related to the moves. Though originally conceived as a martial art, it is also typically practiced for a variety of other personal reasons: competitive wrestling in the format of pushing hands (tui shou), demonstration competitions and achieving greater longevity. As a result, a multitude of training forms exist, both traditional and modern, which correspond to those aims with differing emphasis. Some training forms of Tai Chi are especially known for being practiced with relatively slow movements.

From Wikipedia