Users of Joomla web sites can be broken down into two broad categories;

• Guests
• Registered Users

Guests are simply users of your Joomla web site who managed to navigate their way to your site. Depending on how the site administrator has configured the site, users may be free to browse all the content or restricted to a subset of the content available with some content been reserved for registered users.

Registered users have registered with your site to obtain a username and password. This username and password allows registered users to log into your site, receiving special privileges not available to guests. Registered users are broken down into groups;

• Frontend users
• Backend Users

Frontend Users:

Frontend users are granted certain additional rights over guests, which may include the ability to create and publish content on the web site. We will generally refer to these uses as content providers since their primary goal is to provide content on the web site, not to administer the site or alter its design.

Content providers may provide new content right through the web interface using an embedded WYSIWG editor without any knowledge of HTML coding.

Within this broad classification of content providers are four specific roles, which can be assigned by the site administrator. Those roles are:

Registered

A registered user has no ability to create edit or publish content in a Joomla
web site. They may submit new links for publication and they may have
access to restricted content that is not available to guests.

Author

Authors can create content, signify certain aspects of how the content is to
be displayed and specify the date for when the material should be published.

Editor

An editor has all the abilities of an author plus the ability to edit content of
their own articles as well as that of any other author.

Publisher

Publishers can perform all the duties of authors and editors, plus they have the
ability to actually publish an article.

The default user role is registered user. For frontend users to receive any other role requires the system administrator to change their profile through the backend administrator's panel.

Backend Users

Backend Users are typically thought of as the site administrators. Just as with the frontend users, backend users may have different privileges.

Manager

A manager is basically a publisher with access to the backend administrator's panel. Managers have access to all the content-associated controls in the administrator panel but are not able to change templates, alter page layouts, or add or delete extensions to Joomla. Managers also have no authority to add users or alter existing user profiles.

Administrator

Administrators have a broader range of access than managers. In addition to all the content-related activities that a manager can perform, administrators can add and delete extensions to the web site, change templates or alter page layouts and can even alter user profiles equal to their own permission levels or below. They cannot edit the profiles of Super Administrators or change certain global characteristics of the web site. Indeed, Super Administrators do not even show up in the user manager
when users are logged in as an administrator.

Super Administrator

The Super Administrator has the same kind of power as root in a traditional Linux system and has unrestricted abilities to perform all administrative functions inside of Joomla. Only Super Administrators have the ability to create new users with Super Administrator permissions or to assign Super Administrator permissions to existing users.

The only user that exists after a Joomla! installation is the Super Administrator. The Super Administrator has control over all aspects of a Joomla web site through the backend administrator's panel.