$a == $b Equal TRUE if $a is equal to $b after type juggling.
$a === $b Identical TRUE if $a is equal to $b, and they are of the same type. (introduced in PHP 4)
Source: http://de3.php.net/manual/en/language.o ... arison.php
See also an example: http://php.net/array_search
Related link: PHP and the great "===" operator