==

(Equal) Returns true if $x is equal to $y

$x = 40; 
$y = "40";
var_dump($x == $y); // true

===

(Identical) Returns true if $x is equal to $y, and they are of the same type

$x = 40; 
$y = "40";
var_dump($x === $y); // false

!=

(Not equal) Returns true if $x is not equal to $y

$x = 40; 
$y = "40";
var_dump($x != $y); // false

<>

(Not equal) Returns true if $x is not equal to $y

$x = 40; 
$y = "40";
var_dump($x <> $y); // false

!==

(Not identical) Returns true if $x is not equal to $y, or they are not of the same type

$x = 40; 
$y = "40";
var_dump($x !== $y); // true

>

(Greater than) Returns true if $x is greater than $y

$x = 40; 
$y = 50;
var_dump($x > $y); // false

<

(Less than) Returns true if $x is less than $y

$x = 40; 
$y = 50;
var_dump($x < $y); // true

>=

(Greater than or equal to) Returns true if $x is greater than or equal to $y

$x = 40; 
$y = 50;
var_dump($x >= $y); // false

<=

(Less than or equal to) Returns true if $x is less than or equal to $y

$x = 40; 
$y = 50;
var_dump($x <= $y); // true