The principle of least privilege is an important concept in security. It states that systems and each of their components should be granted only the privileges necessary to perform their intended functions. Here "privilege" means the capability to perform some action, such as executing a command or reading a file.
The principle of least privilege is an important security measure because it limits the damage that can be done by exploiting a vulnerability.
For the Linux, and UNIX operating systems on which Enterprise Server runs, the most important step to achieve a least-privilege configuration is to ensure that processes are not running under an administrative or "superuser" account.