nis - A client/server directory services application developed by Sun Microsystems for UNIX. Network Information System (NIS) acts as a kind of “yellow pages” for locating resources on a TCP/IP internetwork, enabling applications or users to locate and access files and applications anywhere in the network using only a single username and password.
NIS uses remote procedure calls (RPCs) for communication between clients and servers. NIS client programs access NIS servers to locate resources and authenticate resource access.
A newer version called NIS+ includes additional security features. NIS is often used with the Network File System (NFS).