Please clear the theory of Yin and Yang?

My dear friend its nothing but duality

Do your own homework, westerners know little to nothing about Yin and Yang. They think its all about balance, what rubbish. that is only a part of it.

a polar bear in a snow storm

EDIT:

for something to exist there must be something to contrast it with, otherwise it cannot be define. if yin is the thing then yang defines it with its emptiness. therefore there is always a part of yin in yang and vice versa. at the furthest limits of yin you run into yang and vice versa. yin is yang yang is yin

they cannot be seperated.

As an english speaker I'm having problems understanding your question because it lacks some needed detail. Please clear the theory to me sounds like you want to know how they relate but I'm not sure how much you know about either so im unsure where to start. I would say they both have to deal with nature and how it works but of course I can say that about anything really.

Like move on said

It represents the balance

I think of it in scientific terms, rather than metaphysical. For every force, there is an equal and opposite force. The dots represent that nothing can be completely pure. Someone can be good, but will always have that little piece of them that is not, like wise with someone who is "bad"

Think of star wars, if it helps.

It represents the duality of nature, and balance in the universe. Negative (black side) and positive (white side) which balance one another out.

It applies to everything from the cycle of nature to the human persona.

Anyone who is capable of a good act is capable of an equally evil act, and vice versa. Examples: Hitler was capable of incredible evil, but he was also genius enough to do incredible good. It was within his capabilities.

YIN AND YANG

Every person male or female carries male energy and female energy. Means when a man is jealous or in fear from something that it’s the female energy is more pronounce than male. When a female is threatened physically and she defends physically than its male energy more pronounced. Keeping perfect balance is very good for health & mind.

The female energy is receptive, patient, intuitive and sensitive. It can be described as dark, defuse, stationary, and vague. Male energy represents strength, firmness, logic, and rationality. So human beings are psychologically androgynous with latent male and female energies awaiting development.

The Tao symbol of “yin and yang, containing of a circle divided in two equal portion each containing an element of the other.

Since child boy and girl develop these energies boy depend on male energy and girl on female energy. If a boy lives more in female company it develops its intuitive part. Infant have high intuitiveness that is why a young girl’s intuitiveness dissuades a boy from following her heart. Young boy are more aggressive because of female energy integration to male energy. Young girl become more physical action oriented because of male energy integration to female energy. Another way each one is trying to hide the negative side and that become more prominent. A lot of men avoid getting in touch with their emotional side; they avoid thinking from female energy which is the heart because they fear they may not be accepted in society. Female energy plays a crucial role in alternative healing methods even. Aging bodies get infused with harsh energy. Contact with nurturing female energy can slow down the process of ageing. Gandhi Ji was surrounded by young female that supplemented his harmonious peaceful outlook to politics. They both have dark and light side. The dark side of male energy manifests itself with highly competitive and violent. Light side of male energy is protective and outwardly helpful. Dark side of female energy shows itself as weak and insecure while light side shows itself as receptive and nurturing. Men or women who have not integrated their female energy tend to be hard or cold. Men or women who have not integrated their male energy tend to be weak or passive. Perfect balance in both energy keep mind healthy and healthy mind resides in healthy body.

It represents the universal law of balance. Love / hate, strong / weak, black / white, positive / negative, feast / famine ........