What does NAS stand for?
NAS stands for Network-attached Storage. A dedicated storage appliance on the network that shares files over SMB or NFS, so many users and devices can reach the same folders. It works at the file level, unlike a SAN or iSCSI target that presents block storage; most include RAID and snapshots.
A NAS is a storage device with its own network connection that shares files with many clients. Users see folders; underneath, the NAS speaks a file-sharing protocol, usually SMB for Windows clients and NFS for Linux and Unix ones, and manages the disks and the file system itself. Because it works at file level over the ordinary network, it is simple to add and is the usual choice for shared folders and backups in small and mid-sized offices.
NAS in practice: an example
A design studio puts a four-disk NAS on its LAN. Everyone maps the same shared drive, permissions decide who can open the finance folder, and the nightly backup of each workstation is written to another share on the same box.
What NAS is confused with
NAS vs SAN: what is the difference?
A NAS shares files over the normal network: clients ask for a file by name. A SAN hands out raw block storage over a dedicated network, and the server that receives it formats and manages it like a local disk. What SAN stands for
NAS vs DAS: what is the difference?
Direct-attached storage is plugged into one computer, for example by USB or SAS. A NAS is reachable by everyone on the network.
Which exams cover NAS?
NAS is on the official CompTIA acronym list for one of the four exams covered here.
- Network+ N10-009: 1.0 (Networking Concepts).
Each number is a CompTIA exam objective and the name in brackets is its domain. The exam puts the term in a scenario; it does not ask you to recite the expansion.
Check yourself: two practice questions
Written by CertSprint for this page. They are not taken from any exam.
1. Twenty office workers need a shared folder that both Windows and Linux machines can open. Which storage type is the simplest fit?
- Network-attached storage
- A storage area network
- A USB drive on one PC
- A tape library
Show the answer
A. Network-attached storage. A NAS shares files over the existing LAN with SMB and NFS, which is exactly this need. A SAN provides block storage to servers and needs its own design.
2. Which statement describes how a client accesses data on a NAS?
- It reads and writes raw disk blocks
- It requests files by path over a file-sharing protocol
- It boots from the NAS firmware
- It uses a serial console cable
Show the answer
B. It requests files by path over a file-sharing protocol. A NAS works at file level: the client asks for a file and the NAS handles the file system. Block-level access is what a SAN provides.
Sources: NIST glossary: network attached storage; RFC 7530: Network File System (NFS) Version 4 Protocol; Microsoft Learn: Overview of file sharing using the SMB 3 protocol. The acronym and its expansion come from CompTIA's official acronym lists, linked from each exam glossary above. The explanation, example and questions are CertSprint's own, checked against these sources on 11 November 2026.