The flag of South Korea is known as the Taegukgi. It consists of a white field with a central red and blue Taeguk (yin-yang symbol), and four black trigrams at each corner. The white background represents peace and purity. The Taeguk symbol at the center symbolizes the balance between the cosmic forces of yin (blue) and yang (red), reflecting the harmony of opposites. The four trigrams come from the I Ching (Book of Changes), an ancient Chinese text, and represent elements such as heaven, earth, fire, and water: The top left corner trigram symbolizes heaven (☰). The top right corner represents lake or water (☱). The bottom left corner is for earth (☷). The bottom right represents fire (☲). The flag was officially adopted in 1948 and is an emblem of South Korea's ideals and its philosophical roots.