Drupal has a permission system which places users into roles/groups of users. A visitor who is not logged in is an anonymous user and a newly registered user is an authenticated user. An additional role has been added to this installation, an administrator which is given full access on the site. In the original account setup, the root super user account which was created first is not affected by the Drupal permission system.
Some configuration tips:
Note: The default registration permission settings on this site allows anyone to register. Before sharing this site publicly with others and immediately after having students register for the site in class, you should change this setting to at least require administrator moderation of new accounts.
Populating the course: Registration
Assuming that your site is public on the Internet, you probably don't want to leave registration permanently open for anyone on the Internet to join your course site. Leave registration open for the first day of class; then change the user registration setting to "Visitors can create accounts but administrator approval is required." This will allos students joining the course during the add/drop to register with your approval.
Recommended: if your site is public on the Internet, for privacy reasons, encourage students to use a screen name instead of their full names. This little bit of anonymity still puts the writing/writer at risk since the writing is public, but not the student.
Student personal information
Using the profile module, you can require students to provide information about themselves during registration or make some profile information optional. The module will also let you set some fields to " " allowing only the student and a teacher/administrator to see the content of that field on the user's account page. This feature is useful for having students provide personal information such as email address, full name, etc., so that it is not public to other students or the rest of the Internet.