The symbolism of the Korean National Flag originates from an oriental philosophy called Eum-Yang, in Chinese pronunciation Yin-Yang. In Korea, the symbol of ‘Yin and Yang’, and sometimes the flag itself, is called TaeGuk and summarises the thoughts of ‘I Ching’ (called ‘Yeok’ in Korean). The name literally means the flag of ‘Great Extremes’. The central thought is perfect harmony and balance: A continuous movement within the sphere of infinity, resulting in one unit.

The four trigrams at the corners (called ‘Kwe’ in Korean) also represent the concept of opposites and balance. The trigrams are heaven ("Kun" - upper-left) and at the other corner earth ("Kon"), water ("Kam") (upper-right) and at the other corner fire ("Yi"). Looking at symbols of the trigrams, you can see that they are opposites as well. Three unbroken bars (heaven) vs. three broken bars (earth), etc.

Yin means dark and cold, while Yang means bright and hot. A very old Chinese book called Choo-Yuk claims all objects and events in the world are expressed by the movement of yin and yang. For example, the moon is yin while the sun is yang. The earth is yin and the sky is yang. The night is yin and the day is yang. Yin and yang are relative. Therefore, A can be yin with respect to B while A can be yang with respect to C. For example, the spring is yin with respect to the summer and it is at the same time yang with respect to the winter.