What do you mean by divination?

Divination is the basic factor of the Book of Changes. It is divided into Yang (-) and Yin (-), and the three hexagrams overlap to form eight diagrams, namely Gan (Sanyang) and Kun (Sanyin). Eight trigrams overlap again to form sixty-four hexagrams. For example, the "Thai" of Jitai is Shangkun and Xiakun, so "no" means Shangkun and Xiakun; Each hexagram has six hexagrams. Classics include four parts: divinatory symbols, divinatory symbols, divinatory symbols and divinatory symbols. Gua Ci is to explain the meaning of all hexagrams, and Yi Ci is to explain the meaning of each hexagram.