Super User is a user that has full access to all administration functions in Joomla. This tag can be considered a sub-tag of the users tag, which shall be used for all user, user-management, ACL related questions.
Note about using this tag in JSE:
This tag can be considered a sub-tag of the users tag, which shall be used for all user, user-management, ACL related questions.
What is Super User in Joomla
A Super User (or super administrator, or super admin) in Joomla, is a user that belongs to the Super Administrator user-group.
This group allows access to all administration functions. Only another Super Administrator can create or edit a Super Administrator user account. Full access to ALL AREAS is given to Super Administrators, and once created they cannot be as easily deleted.
It might not be obvious, but you have to change the user's group to something other than Super Administrator first. Then you can delete them.
Generally it is recommended that only experienced users should be granted Super Users rights.