The Network Information Service (NIS) is a system which provides network
information (login names, passwords, home directories, group information)
to all of the machines on a network. NIS can enable users to login on
any machine on the network, as long as the machine has the NIS client
programs running and the user's password is recorded in the NIS passwd
database. NIS was formerly known as Sun Yellow Pages (YP).

This package provides the NIS server, which will need to be running on
your network. NIS clients do not need to be running the server.

Install ypserv if you need an NIS server for your network. You'll also
need to install the yp-tools and ypbind packages onto any NIS client
machines.