wht's does => mean

hi friends..,
well I'm noob in PHP...,
i was going through a side code and in it i noticed the sigh '=>',
i know '->' means an arrow... but what is => and what is the use of it...

part of teh code is given below...

" set_snapshot(array('mode' => 'SSL', 'page' => FILENAME_CHECKOUT_PAYMENT)"

thx..

The arrow -> as you have called it is a pathname seperator used when referring to variables or functions within an instance of a class.

The => symbol is the key value operator. It defines the relationship between a key and it's value. So $key => $value. You would define this relationship in an array.