NFS is a client/server distributed file system developed by Sun Microsystems that has become the standard file system for various implementations of the UNIX platform. Network File System (NFS) lets users transparently store and access information on both local and remote computers on a TCP/IP internetwork.
NFS uses remote procedure calls (RPCs) running over User Datagram Protocol (UDP) on server port 2049 for stateless communication between clients and file servers on the network. NFS clients (client machines running NFS client software) import remote file systems from NFS servers, while the NFS servers export local file systems to clients.
Machines running the NFS client can connect to NFS servers and read, modify, copy, move, or delete files on the server using RPC requests such as READ, WRITE, CREATE, and MKDIR. To the user accessing the remote file system from the client, the files appear to be stored locally on his or her system.
Before a user can access files within the directory structure on the local UNIX file system of the NFS server, the administrator must mount the portions of the local UNIX file system that will be made accessible to clients and assign appropriate user privileges.