SU and SUDO
Just to correct you here, SU is *NOT* "Run as root" that's effectively what SUDO is for, SU stands for "Switch user" when it's run on its own it switches to the root account, but if you specify a username it will switch to that user (i.e. "su bob" will switch to the user bob). By contrast, SUDO will run the command as root and then return you to the original state (i.e. on the command line it'll run the command as root and then put you back to your normal user).