Simple visitors - common persons, which surf the Internet and visit the website sometimes or which have visited it a few times.
Users - registered visitors, possessing a username and a password.
Super users - users, having a higher privilege, which allows to edit all the website (= editors).

• creating users, who possess exeptional rights, and providing them with a password and a username. "Exeptional rights" means wider user's activity frames, comparing with other users: a possibility to see certain website's menu parts, to reach specific information (restricted to others), obtain a voting right in various website questionings, etc.
• granting certain website management privileges for several users, forming their groups, changing their functions, deleting them.