2.1 User Accounts
2.1.1 Account types
Root Account
There are basically two types of user accounts on a UNIX computer, the root or "superuser" account, and a regular user account. The root account is the system administration account and is set up by the installation process. It is the only account on the system when it is first installed. The root login account owns all system files and has access to all files. It is similar to the Administrator account with Windows NT/2000 or the Admin account with Novell NetWare. 

The root account is used to create new users, manage file systems, install software and perform other high-level system administration tasks. Since it is "all powerful," the root account should be used sparingly. Most UNIX "superusers" have a regular user account that they use on a daily basis and only login as root when necessary to perform administrative tasks. 

Regular User Accounts
Regular user accounts are created and maintained by the system administrator when logged on as root. Every user who needs access to the system must have a user account to login and use the computer. Regular users can run applications and customize their working environment. They can also create and modify files in their home directory.