The  Book of Changes  is one of the six principal Confucian classics in ancient China, originally named  Zhou Yi  or simply  Yi . It was commonly known as the  Yijing  (or  I Ching ) during the Han Dynasty (206 BC–AD 220). There are two primary interpretations for the character  yi : simplicity or changes. The latter means that the book was used to decipher the changing patterns of divination results. There are also two explanations for the character  zhou . One indicates the text's origin in the Zhou Dynasty (1046–256 BC) when divination was popular. In contrast, the other is understood as "universality," used to interpret all the changes in the universe. The Han Dynasty version consisted of  jing  (which was the main content) and  zhuan  (commentaries for the  jing ).