A 5 minute clip to explain a little about yin and yang.
The Taoists define yin yang as polar energies that fluctuate and interact in constant motion. If you observe the symbol of two curved teardrops, you will see the black (yin) side descending and the white (yang) side ascending. There is an inner circle within each of the opposite color. There is a movement within the symbol to convey that whenever yin and yang come together, they separate only to reconnect as one.