The Book of Changes, also known as the Book of Changes, is one of the oldest classics in China and is known as the head of the group of classics and the source of the great Tao. The whole book is divided into two parts: "Classics" and "Biographies". The Book of Changes is based on the two lines of yin and yang, and the three lines form the Eight Trigrams. The combination of the Eight Trigrams gives rise to the sixty-four hexagrams, revealing the laws of change and development of all things in the universe.