It was always confusing me.
Su = switch user
Superuser = elevated status, administrator.
Superuser.apk = firewall
If you have superuser status, you are root enabled or "rooted". Any app you run also has the ability to make changes to system areas.
If you have installed superuser.apk or supersu.apk, you have a firewall to root and programs must ask your permission.
Towelroot elevates your status to superuser (administrator) but does not install superuser.apk.
sent by mirrorflash Morse code