Definition: Session_destroy() destroys all of the data associated with the current session, however it does not unset any of the global variables associated with the session, nor does it unset the session cookie. It is often used with session_unset() to more thoroughly remove the session.
Also Known As: Destroy PHP Session
Examples:
<?php
// you have to open the session first
session_start();
//remove all the variables in the session
session_unset();
// destroy the session
session_destroy();
?> 