Tai chi is an internal Chinese martial art practiced for defense training, health benefits, and meditation. The term taiji is a Chinese cosmological concept for the flux of yin and yang, Taijiquan is a fist system based on the dynamic relationship between polarities (Yin and Yang). Today, tai chi has enthusiastic practitioners worldwide. Most modern styles of tai chi trace their development to one or more of the five traditional schools: Chen, Yang, Wu (Hao), Wu, and Sun.