The Korean flag is called Taegeukgi.
Its design symbolizing the principles of yin and yang is from oriental philosophy. The circle in the center of the flag is divided into two equal parts.

The upper red section represents the positive cosmic forces of yang.
Conversely, the lower blue section represents the negativecosmic forces of yin.

The two forces together embody the concepts of continual movement, balance, and harmony that characterize the sphere of infinity. The circle is surrounded by four trigrams, one in each corner. Each trigram symbolizes one of the four universal elements.