In Chinese philosophy, yin and yang are concepts used to describe how apparently opposite or contrary forces are actually complementary, interconnected, and interdependent giving rise to each other as they interrelate. Many tangible dualities (such as light and dark, fire and water, and male and female) are thought of as physical manifestations of the duality of yin and yang. This duality 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.
Yin is the negative/passive/female principle in nature, and may allude to many other concepts e.g. the moon, shaded orientation, something covert or concealed, "of the netherworld", overcast or sinister.
Yang is the positive/active/male principle in nature, and may allude to many other concepts e.g. the sun, open, overt, and "belonging to this world".
See Special:Whatlinkshere/Etymology:Yin and yang for a list of articles using this term.