Editing Network-attached storage (section)

=== Comparing with SAN ===
[[File:SANvsNAS.svg|thumb|Visual differentiation of NAS and [[storage area network|SAN]] use in network architecture]]
NAS provides both storage and a [[file system]]. This is often contrasted with SAN ([[storage area network]]), which provides only block-based storage and leaves file system concerns on the "client" side. SAN protocols include [[Fibre Channel]], [[iSCSI]], [[ATA over Ethernet]] (AoE) and [[HyperSCSI]].

One way to loosely conceptualize the difference between a NAS and a SAN is that NAS appears to the client OS (operating system) as a [[file server]] (the client can [[drive mapping|map]] network drives to shares on that server) whereas a disk available through a SAN still appears to the client OS as a disk, visible in disk and volume management utilities (along with client's local disks), and available to be formatted with a file system and [[Mount (computing)|mounted]].

Despite their differences, SAN and NAS are not mutually exclusive and may be combined as a SAN-NAS hybrid, offering both file-level protocols (NAS) and block-level protocols (SAN) from the same system{{citation_needed|date=May 2025}}. A [[shared disk file system]] can also be run on top of a SAN to provide filesystem services.