When new users register at a Joomla website, they can be classified as a specific type of user depending upon how the site administrators originally set up user registration. Joomla offers four different public front-end settings, they are: Registered, Author, Editor and Publisher. Additionally, there are three different levels of back end settings: Manager, Administrator and Super Administrator.
Here is an explanation of the front- end user settings:
"Registered" users can see content that non-registered users cannot, but they do not have the ability to edit anything. Users registered as "Author" can create articles and edit the ones they created, but they cannot edit anything else, including other Authors. "Editors" are virtually the same as Authors, but they can edit all Author articles, not just their own. And finally "Publishers" are the same as Editors, but they can also determine whether articles can be published, unpublished or deleted.
Before we go on, I have assumed a couple of things. First, you have a current version of Joomla already installed and you can access the administrator area. Additionally, your site is already configured to register visitors.
The first thing you will do is log on the administrator area of your site and go to the "Site" menu and click on "User Manager". Next locate the user that you want to update. If you have a very large list of users, you may wish to type their username or their name in to the "Filter" text box to locate them.
Once you have located the user, click on their name and in the "Group" window, choose which group you wish to grant them access to. Next, decide if the user should "Receive System E-mails" which are emails generated by Joomla, usually these are only sent to Administrators, but you can grant anyone access to them if you wish.
While you have this users account open, you can choose what their front-end language will be if this is a multi language site. You can also choose that type of front-end editor they will be using such as TinyMCE or none at all. You may also choose what kind of help site they can access and what time zone they are in. Now click "Save" to have the settings for that user preserved.