What is the difference between the mysqli_set_charset function in mysqli and setting SETNAMES in SQL?

I used to use the SETNAMESutf8 statement to set the character set before each connection, but in mysqli There Is A mysqli_set_charset function that does this. I thought it was exactly the same as what I set myself, however, Thisisthepreferred is found in its document note... I used to use Set names utf8Statement to set the character set, but in MysqliThere is Mysqli_set_charsetThe function does this. I thought it was exactly the same as what I set myself, but in its document note, I found that

This is the preferred way to change the charset. Using mysqli_query () to set it (such as set names utf8) is not recommended.

The two are different. What is the difference?

Reply content:

I used to useSet names utf8Statement to set the character set, but inMysqliThere isMysqli_set_charsetThe function does this. I thought it was exactly the same as what I set myself, but in its document note, I found that

This is the preferred way to change the charset. Using mysqli_query () to set it (such as set names utf8) is not recommended.

The two are different. What is the difference?