If you allow visitors to your site the ability to add content via article submissions on the front-end, you will want to restrict those authors to editing only their own work. You will not want individual authors editing other peoples work. The last thing you would want is to have someone editing your hard work without your permission. This article will explain how to limit writers to editing only articles that they have written and submitted to your Joomla site.
For this article, I assume that you have a current version of Joomla installed and know how to access and use the administrator area.
The first thing you will want to do is to log on to the back end administration area and access the "User Manager" which is located under the "Site" menu. Next, you will locate the user whose permissions you wish to change. If you have a large user list, you may want to use the "Filter" on the top of the page to find them.
Once you have located the user, click on their name and make sure that they are listed under the "Group" area as "Author". The default Joomla setup allows visitors to register as either a registered user, an author, an editor or as a publisher. If you have set up the user registration to default to "author", then you should not have to make any changes. But if the initial setup was set to any of the other settings, you will want to manually change them as described above.
After you make the change, click "save" and exit the administration area. Now any users that have been made an "author" will only be allowed to edit their own work. If you want to allow your users the ability to edit all authors, choose the "Editor" group. This will allow them to edit, but will not allow them to publish, unpublish or delete articles written by any author on the site.