The Yin-Yang is the most prevalent symbol of Taoism. It does not represent Taoism, however, it merely reflects the Taoist process.
The black part of the symbol represents Yin and the white represents Yang. The outer circle of the symbol represents 'everything'. It's important to remember that one cannot exist without the other. For an explanation of this, please read the quote from the Tao Te Ching at the bottom of the page.
The shape of the symbol gives an impression of cyclical movement and represents the interation of the two energies.
The dots of opposite colour in each side represent the fact that nothing in life is strictly black and white, and that there are always factors of both in each situation.
For examples of Yin and Yang, please go to this website:
"Under heaven, all can see beauty as beauty only because there is ugliness.
All can know good as good only because there is evil.
Therefore, having and not having arise together.
Difficult and easy compliment each other.
Long and short contrast each other;
High and low rest upon each other;
Voice and sound harmonize each other;
Front and back follow one another.
Therefore the sage goes about doing nothing, teaching no-talking.
The myriad of things rise and fall without cease,
Creating, yet no possessing,
Working, yet not taking credit.
Work is done, then forgotten.
Therefore it lasts forever."
Tao Te Ching, Chapter 2