The gvuser account log-in credentials are stored locally on the workstation. It is primarily used to allow a user to log in without a network connection or perform maintenance if the network is down.
The gvadmin account is local, like gvuser but has the traditional GNOME desktop with none of the lockdown or restrictions of the Groovix desktop; this account also includes links to Admin tools, etc. There is no need to log in as gvadmin unless directed to do so or you specifically need access to certain administrative tools. This account does not delete changes made in-between logouts; make sure to always close Firefox before logging out of a session with gvadmin.
The groovixtemplateuser account is used solely for the purpose of making changes to the public user environment. This account does not delete changes made in-between logouts; make sure to always close Firefox before logging out of a session with groovixtemplateuser.