NIS (Network Information System) was developed by Sun Microsystem which is a network naming and administration system for smaller networks. The later version NIS+ provides additional security and other facilities. Using NIS, each host client or server computer in the system has knowledge about the entire system. In the network, the user at any host can get access to files or applications on any host with a single user identification and password. Network Information System is similar to the Internet’s domain name system (DNS) but somewhat simpler and designed for a smaller network. It’s intended for use on local area networks.
NIS uses the client/server model and the Remote Procedure Call (RPC) interface for communication between hosts. NIS consists of a server, a library of client programs, and some administrative tools. NIS is often used with the Network File System (NFS). NIS is a UNIX-based program.
NIS was originally called as Yellow Pages but this name already had a trademark, so it was changed to Network Information System. It is still sometimes referred to by the initials: “YP”. Although Sun and others offer proprietary versions, most NIS code has been released into the public domain and there are freeware versions available.