high-end NAS's and home network storage would be accessed the same way (i.e. NFS/CIFS/SAMBA).
The real difference with high-end NAS is more storage (terabytes) and appliance-centric (i.e. web based interface etc.) for easy management, deployment and supportability, plus quota and some have iSCSI options as well. Most of them run Windows Storage Server or a lock-down linux kernel.