MySQL character set and proofing rules

A character set is a set of characters and encodings, which are a set of rules for comparing character sets.

So the character set has two parts that make up the character set and the corresponding encoding set. For example, now there are these characters: a B A B, assuming that they correspond to codes 00, 01, 10, 11, then Abab and [00,01,10,11] form a set of character sets. Then the function of proofreading rules is the rule a<b or a>b. Assuming we stipulate a<b,a=a,b=b, this rule constitutes a collation. Of course, we can also stipulate that a>b,a>a,a>b is also a set of proofreading rules. So a character set can have multiple sets of proofing rules.