Yin and Yang are essential to understanding Wing Chun and Kung Fu. The concepts originated from observing the natural world, and the way in which it is divided into dependent opposites. “Light” cannot exist without “dark,” “up” cannot exist without “down,” and “inside” cannot exist without “outside.” Yin and Yang are not physical objects, but rather are descriptors that show the relationship or dynamic interaction with an opposite. Yin represents darkness, stillness, cold, passiveness, softness, quiet, and potential. Yang represents light, action, heat, aggression, firmness, loud,ness and expression. The Taiji Jee symbol illustrates that these two forces are not mutually exclusive but are constantly interacting and even transforming from one to another. The blending shape in the symbol shows that there is a balance between these two qualities.