What is four pillars and eight characters?

The four pillars are composed of heavenly stems and earthly branches, with a total of eight words, four days and four branches, such as:

Chen Wuding Si Gengwu Chen Geng

In the four pillars of heavenly stems and earthly branches, who is born is the center, that is, the Ten Gods are listed with "Gengwu" as the center. What are the Ten Gods, namely, to compete with others, to rob money, to be rich, to be partial to talents, to be an official, to be a god of food, to hurt an official, to be printed and to be partial to talents (also known as Xiao Shen). According to the principle of five elements, those who scold me are "officials" and "seven kills", those who give birth to me are "positive prints" and "partial prints", those who scold me are "righteous wealth" and "partial talents", those who give birth to me are "gourmets" and "hurting officials", and those who are with me are "competing with each other and robbing money". "Tougan" means that some of the "Ten Gods" in the eight characters reveal heavenly dryness. Take the above-mentioned eight characters as an example. "Thoroughly dry" is "E, D and G", which are "partial printing, official position and shoulder to shoulder" of "Gengwu (Japanese Lord)" respectively. "Chen, Si, Wu and Chen" are the earthly branches.