What I See is What You Get

In Chinese philosophy, the concept of yin yang is used to describe how polar or seemingly contrary forces are interconnected and interdependent in the natural world, and how they give rise to each other in turn. The concept lies at the origins of many branches of classical Chinese science and philosophy, as well as being a primary guideline of traditional Chinese medicine and a central principle of different forms of Chinese martial arts and exercise, such as baguazhang, taijiquan (tai chi), and qigong (Chi Kung) and of I Ching divination. Many natural dualities — e.g. dark and light, female and male, low and high, cold and hot — are thought of as manifestations of yin and yang (respectively).
Source: Wikipedia