Passing 2 GET variables

If I do 2 get variables would it be

http://www.website.com?catalog&item=14

so I would have 2 get variables

catalog

and

item

than to check the get value

would it be

if (isset($_GET['item'])){
$thing= $_GET['item'];
echo '$thing';
}
and thing would be equal to 14?

Thanks for all your help

I figured it out