Some color:
MacOSMac OS X has roots in BSD UNIX, a.k.a. the UNIX that came out of U of C BerkeleyUC Berkeley. They had a group of trusted people that could become superuser by using the su
command. So they coded their UNIX to only allow people in this specific group to become superuser using su
. They chose the groupname 'wheel', supposedly reference to other systems that had WHEEL, possibly a reference to being a 'big wheel''big wheel'
It's less important now that you have the GUI authorization popups and sudo. You can use sudo without being in wheel group iI believe.
As far as how to change to wheel, chgrp
should be your friend, once you're root.