What is 10 Deities (十神)?

10 Deities? Does it refer to 10 different gods/deities? If yes, who are they?

If no, what the earth is 10 deities?

Definitely, 10 deities does not refer to deity or god. It is, in fact, the 10 relationships that the Day Master (日元 ie, the owner of the bazi chart) with the individual 10 Heavenly Stems (十天干).

Simply put it, 10 deities are the 10 names assigned to such 10 relationships.

I supposed our ancestor used the term 'deities' to enhance its credibility.