In Chinese philosophy, yin and yang are two categories symbiotic and complementary, which can be found in all aspects of life and the universe. This notion of complementarity is important, especially as Western thought more likely to think the dualism in the form of complementary opposition. In Chinese cosmology, these are the two entities that follow the original breath qi at work in all things.
Yin is associated with the moon which represents the feminine side of nature;
Yang is associated with the Sun represents the masculine side of nature.
According Shuowen Jiezi, dictionary of the Han dynasty, the meaning of yin is "dark, [as] the southern or northern water of the mountain" that yang is "high brightness".
Some have proposed that the terms yin and yang come from the Sanskrit word linga and yoni. Nevertheless, they appear before the introduction of Buddhism (vehicle of Indian culture) in China. They come in effect in chapter 42 of Dao De Jing: "The Dao gives birth to one, one to two, 2-3, three in the ten thousand things and beings, ten thousand things and beings bear the yang and yin embrace. "
The yin-yang in China called "yin yang fish", the most common form of Taijitu of Taoist and Neo-Confucian, Tao is the result of the dynamics of these two principles, unity beyond the dualism .
Points of opposite colors, known in Chinese medicine biaoli, recall that these two concepts are related, succeed each other and that one exists thanks to the other.
From the analytical approach of considering separately the Yin and Yang, biaoli sufficient to characterize the Confucian thought and its specific advantage - friendship - in relation to the dualism which is too often reduced Western culture , and approaches Cartesian or Christian - other dualism, dual source of stress.
Friendship (between points of views or between physical environments) is the principle which allows entities (legal or natural) opposite communicate.
Anything can be described in terms of yin and yang, which are:
Related opposition, knowing that, as shown Taijitu, either carries within it the germ of another;
in interdependent relationship, one only being conceivable without the other; excess or deficiency of one of the consequences on the other and an imbalance of the whole;
related to generation and transfer from one to another, such as when the day gives way to night;
yin and yang can each be divided into sub-elements yin and yang, so if one distinguishes only two categories in the concept of temperature, cold is yin and yang heat, but it is possible to subdivide the concept of heat in two according to some criterion (eg supportability), and separate heat and warmth yin yang.
It is not absolute correspondence, since they are assigned only within a given pair of opposites.
Thus, we can not really say that something is Yin, Yang is anything else. It would be more accurate to say that something is more Yin in relation to something else which is more Yang. For example, the upward movement is Yang in relation to the downward movement which is Yin. In every thing there is the Yin and Yang, as exemplified by the famous symbol of Tai Ji, as it is the interaction of these two forces that create movement, Qi, energy. And so to paraphrase an expert in quantum physics: matter and energy are actually one and the same thing.
Source: Wikipedia as always. You'll understand I think I like this site! lol!