Network File System (NFS) is a file system protocol. It was originally developed by Sun Microsystems in 1984. Using NFS, a user on a client computer can access files over a network in the same way as if they were attached to its local disks. NFS uses the Open Network Computing Remote Procedure Call (ONC RPC) system. The Network File System is an open standard defined in RFCs. That way, anyone can implement the protocol.