In PHP, we specify variables with a dollar ($) sign. Even here you can deduce that PHP is a very rich language.

A list of rules that you must follow when defining a variable;

1) You cannot use characters other than letters, numbers, and underscores (_).

2) You cannot initialize the variable name with a number. ($1 variable is false, $variable1 is true)

3) PHP distinguishes variable names, so $variable is not the same as $VaRiAbLe.

All terms matching these three rules can be a variable names.

Here are a few examples of suitable variables: $fruits, $mail_box, $easy1, $x, $_php