To share files using NFS, you first need to set up an NFS server. This NFS server can then "export" filesystems. When a filesystem is exported, it means that it is made available to be accessed by other systems on the LAN. Then, any authorized system that is also set up as an NFS client can mount this exported filesystem using the standard "mount" command. After the mount completes, the remote filesystem is "grafted in" in the same way that a locally-mounted filesystem (like /mnt/cdrom) would be after it is mounted. The fact that all of the file data is being read from the NFS server rather than from a disk is simply not an issue to any standard Linux application. Everything simply works.