The administrator tag is a special user tag that grants its holder access to almost all aspects of the admin panel. Along with owner, it is a user tag that is added to websites by default.
It is important that you give administrator access only to users you explicitly trust. The admin tag essentially makes users co-owners of your website; they have complete authority to ban and IP ban others, as well as delete modules and pages.
How to make a user an admin
Like all other user tags, you can add the 'admin tag through your website's /admin/users page. Simply find the user you wish to tag, check the box next to their name, and use the "User Tools" button to make the user an administrator. Please make sure that you read the security section above before making any user an administrator.