A set of protocols that run over a network and offer support for file transfer and access, and for paging. The system was originally developed by Sun Microsystems Inc. to allow workstations without disks to access files on other machines as if they were on local disks. The system became a de facto standard, and new versions of NFS are now controlled by IETF.

http://tools.ietf.org/html/rfc3530 The NFS (version 4) specification