Thisis a chinese symbol. sometimes called Tai chi symbol
It shows the power one will gain when his or her ying(soft , feminine, etc) and yang (hard, masculine etc) is balanced.
This symbol is extaneously used in KungFu films
I look at ying yang as the perfect circle of life, some times your life is down the bottom the it does the prfect circl then your life comes good at the top...