That's an excellent rundown, Picklesworth. It equates (it seems to me) to adminstrator, user and guest accounts in Windows.

The thing with Linux is that it couches perfectly ordinary ideas in obscure terms.

In one post here, someone pointed out that the idea behind 'root' was to keep 'normal' people out of the system. The trouble with the latest ITs is that they are being bought by 'normal' people and some old Linux buffers feel their hierarchy is under threat.