Network Attached Storage (NAS) is a file-level storage architecture where 1 or more servers with dedicated disks store data and share it with many clients connected to a network. NAS is 1 of the 3 main storage architectures along with storage area networks (SAN) and direct-attached storage (DAS) and is the only 1 that’s both inherently networked and fully responsible for an entire network’s storage.
Compare NAS to more familiar storage volumes, like your PC’s hard drive, external drive, CD, or USB flash drive. A NAS architecture allows you to store and share file-based data, much like any storage volume. But while your hard drive, external drive, CD, or flash drive can only connect to 1 device at a time, NAS is networked to support many devices simultaneously.
Network Attached Storage units are built to serve data as files. Although they’re technically able to complete general server tasks as well, NAS units run software that protects data and handles permissions—that’s it. This is why NAS units don’t need a full-featured operating system. Most NAS units contain an embedded, lightweight operating system fine-tuned for data storage and presentation.
To present these files, a NAS unit uses standard file-based protocols, such as Network File System (NFS), Server Message Block (SMB), Common Internet File System (CIFS), and/or Apple Filing Protocol (AFP) which are the protocols used to communicate with Linux® and UNIX, Microsoft Windows, and Apple devices, respectively.