Network Information Service

The Network Information Service (NIS), formerly Yellow Pages, is Sun Microsystems' client-server protocol for distributing system configuration data such as user and host names between computers on a network. Sun licensed the technology to other Unix vendors.

History
Since the name "" was a registered trademark of AT&T in the United States, and of in the United Kingdom, for their respective commercial telephone directories, Sun changed the name of their system to NIS, though all the commands and functions still start with "yp", such as ,  , and. NIS was eventually superseded by and then LDAP.