When administering a home machine, the user must perform some tasks as the root user or by acquiring effective root privileges via a setuid program, such as sudo or su. A setuid program is one that operates with the user ID (UID) of the program's owner rather than the user operating the program. Such programs are denoted by a lower case s in the owner section of a long format listing, as in the following example:

         -rwsr-xr-x 1 root root 47324 May 1 08:09 /bin/su 
      

For the system administrators of an organization, however, choices must be made as to how much administrative access users within the organization should have to their machine. Through a PAM module called pam_console.so, some activities normally reserved only for the root user, such as rebooting and mounting removable media are allowed for the first user that logs in at the physical console (see the chapter titled Pluggable Authentication Modules (PAM) in the Red Hat Enterprise Linux Reference Guide for more about the pam_console.so module.) However, other important system administration tasks such as altering network settings, configuring a new mouse, or mounting network devices are not possible without administrative priveleges. As a result, system administrators must decide how much access the users on their network should receive.