My friend, to put it simply, Yin and Yang are the ancient people's high summaries of the world. According to western philosophy, Yin is noumenon and Yang is function. Everything in the universe can be summarized as ontology and function, and the relationship between ontology and function is called body-use relationship. Ontology is real matter, and functions, such as the color you see, and the invisible interaction between matter and time, are all functions. Matter comes first and function comes second.

From the perspective of traditional Chinese medicine, yin represents matter, which constitutes the human body, and yang represents function. For example, yin deficiency means deficiency of qi, blood and body fluid, while yang deficiency means functional decline. Syndrome of lower, cold, interior and deficiency are all yin, while syndrome of upper, warm, exterior and excess belong to yang. But from a different perspective, it is different. For example, exterior-interior syndrome is yang syndrome and exterior-interior syndrome is yin syndrome. If yin and yang belong to the same category, the same pair, it makes sense. There are also five zang-organs, which belong to yin and six fu-organs belong to yang, because the five zang-organs are mainly hidden and the six fu-organs are mainly collected. If you are interested, you can watch the basic theory of traditional Chinese medicine or videos. Youku you