It is very easy to pass values in the URL as a query string, and get those values to a PHP processor file.
For example, if we want to pass a tracking session ID in the URL, such as:
http://www.phpdebutant.com/tracking.php?session=ABC123
In our tracking.php, we can print out the value that is passed in via the URL by referencing to $_GET[session] or $_REQUEST[session] variable:
echo $_REQUEST[session];