= the assignment operator,
== the ‘equal’ comparison operator and
=== the ‘identical’ comparison operator.
$a = $b Assign Sets $a to be equal to $b. $a == $b Equal TRUE if $a is equal to $b. $a === $b Identical TRUE if $a is equal to $b, and they are of the same type. (introduced in PHP 4)
For more info on the need for
===, and situations to use each, look at the docs.