From Joomla! Documentation
Joomla! maintains two primary classifications of user groups. The classifications are primarily Front-end (site) and Back-end (administration) user groups. Front-end users are only allowed to log in using the public facing side of the website. Back-end users are allowed to log in on the administrative side of the web site. As a result these users are also referred to as administrative users, or admins.
Administrative logins are available by default at
Back-end users are further separated into 2 groups
- Super Users
The most privileged of these users belong to the Super Users group. Super Users have the highest privilege level and can make changes or add new features or content to any section of a Joomla! site.
Points to note on Super Users
- The default Super Users is 'admin' and is installed with every Joomla! site
- Super Users are able to log in on the Front-end or Back-end of the site
- A Joomla! site may have more than one designated Super Users