6.3. System Accounts

System users are those used to run services such as DNS, mail, web servers, and so forth. The reason for this is security, as if all services ran as the superuser, they could act without restriction.

Examples of system users are daemon, operator, bind (for the Domain Name Service), and news. Often sysadmins create httpd to run web servers they install.

nobody is the generic unprivileged system user, but the more services that use nobody, the more privileged it becomes.