Original: Network File System (NFS) is a network file system protocol originally developed by Sun Microsystems in 1984,  allowing a user on a client computer to access files over a network in a manner similar to how local storage is accessed.
Simplified: Network File System (NFS) is a network file system protocol. 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.