In conventional UNIX systems, the root user, also referred to as superuser, is omnipotent, with the ability to read and write to any file, run all programs, and send kill signals to any process. Solaris role-based access control (RBAC) is an alternative to the all-or-nothing superuser model. RBAC uses the security principle of least privilege, which is that no user should be given more privilege than necessary for performing his or her job.
RBAC enables an organization to separate superuser capabilities and package them into special user accounts or roles for assignment to specific individuals. This separation and packaging enables a variety of security policies. Accounts can be set up for special-purpose administrators in such areas as security, networking, firewall, backups, and system operation.