What is the difference between the Admin user, Root, and standard users?
The main differences between the different classes of users is based on what permissions that user has. A normal user can only affect his or her own files, where the Admin user can affect some system files. The root user has the ability to control anything, including files owned by other users. Because of the power the root user has, the root user can only access the server using SSH, and does not have FTP or E-mail access. For more information on the abilities of different users, see VPS2 Users.