"In this article we introduce Network Information System (NIS) in brief and describe how to setup NIS on a Linux system.
When running a local area network, one of the goals is usually to provide an environment to the users that make the
network transparent. An important step for this is to keep vital data such as user account information (e.g. /etc/hosts,
/etc/passwd and /etc/group files) synchronized between all hosts. For host name resolution, a powerful and sophisticated
service - DNS exists. For other tasks, there is no such specialized service. Moreover, if you manage only a small closed
intranet without Internet connectivity, setting up DNS may not seem worth the trouble for many administrators." More at FreeOS.com.