MySQL中單引號和反引號的區別是什麼？

之前在MySQL建表和查詢的時候都用的單引號，後來發現有問題，同學提醒要用反引號，最近發現反引號也會出問題：

1.

2.

在網上看到有說，反引號是為了區分MySQL的保留字和普通字元，這樣的話第2個可以解釋，但是第1個是為什麼呢。

其實單引號和反引號的實際不同是什麼？MySQL在對這兩個符號的操作是怎樣的？

求解，謝謝。

注意學習。

Certain objects within MySQL, including database, table, index,
column, alias, view, stored procedure, partition, tablespace, and
other object names are known as identifiers

An identifier may be quoted or unquoted. If an identifier contains special characters or is a reserved word, you must quote it whenever you refer to it.

The identifier quote character is the backtick (「`」):

MySQL :: MySQL 5.5 Reference Manual :: 9.2 Schema Object Names

A string is a sequence of bytes or characters, enclosed within
either single quote (「"」) or
double quote (「"」) characters

MySQL :: MySQL 5.5 Reference Manual :: 9.1.1 String Literals