Hi! I'm new to UBUNTU!

[Chan Chung Hang Christopher]

> The su or superuser account gives root (admin) permissions when you use
> it.  At the inception of Ubuntu, it was decided to use the 'sudo'
> command to obtain root permissions as this reduced the possibility of
> of root permissions being misused (as I understood matters).  Also, you
> can't login as root straight from login screen.

More like less passwords to remember. You can still enable the root 
account and therefore su. I'm not going to get into the more/less secure 
flamewar so I am staying mum on that score.