Yin and yang have no fixed, precise definition. Instead, they refer to two complementary concepts which include the relationships of: positive and negative; dynamic and inert; creative and destructive; obvious and subtle; and kinetic and potential.
It reminds us that seemingly opposing forces are bound together and interdependent in the natural world, giving rise to each other in turn. The concept lies at the heart of many branches of classic Chinese science and philosophy, as well as being a primary guideline of Traditional Chinese Medicine.
The basic premise of yin and yang is the notion that the only constant factor in the universe is change. Nothing remains the same; no disease, no condition, no emotion, no treatment or diagnosis. Everything is constantly changing.
Yin represents that which endures, nourishes and supports growth. It also refers to something contracting and moving inward, such as calm rather than activity.
Yang, on the other hand, is all that is creative and generating; it develops and expands.
Here are a few examples:
It is believed that yin and yang exists in everything.
Yin and yang are not static concepts. They are constantly influencing each other. There is always some element of yin within yang and vice versa. Look closely at the picture of the Yin and Yang symbol and you will see the dot of Yin within Yang and the dot of Yang with Yin.
In Traditional Chinese Medicine, yin and yang refer to energies and functioning modes of organs and body functions. Your healthy state is created by the right balance of yin and yang. Therefore, it is advisable to make choices that contribute to balance in our lives.