root, Groups, and Management
Unix security has been considered somewhat coarse because one superuser, root, can do anything. Other users are lowly peons who endure the shackles root places upon them. The problem is, root doesn't have a wide variety of shackles on hand and can't individualize them very well. While there is some truth to this, a decent administrator can combine groups and permissions to handle almost any problem securely.
The root Password
Certain actions require absolute control of the system, including manipulating core system files such as the kernel, device drivers, and authentication systems. Such activities are designed to be performed by root.
To use the root password, you can either log in as root at a console login prompt ...