Network File System (NFS) is a way to share files between machines on a network as if the files were located on your local hard drive. Red Hat Linux can be both an NFS server and an NFS client, which means that it can export filesystems to other systems, and mount filesystems exported from other machines.
NFS is useful for sharing directories of files between multiple users on the same network. For example, a group of users working on the same project can have access to the files for that project using a shared portion of the NFS filesystem (commonly known as an NFS share) mounted in the directory /myproject. To access the shared files, the user goes into the /myproject directory on his machine. There are no passwords to enter or special commands to remember. The user works as if the directory is on his local machine.