Network-attached storage (NAS) is a dedicated hard disk storage device that is set up with its own network address and provides file-based data storage services to other devices on the network.
A network-attached storage device is attached to a local area network and assigned an IP address, allowing both application programming and files to be served faster because they are not competing for processor resources. NAS devices are usually configured with a web browser and do not have a keyboard or display.
Network-attached storage consists of hard disk storage, including multi-disk RAID systems. NAS software can usually handle a number of network protocols, including Microsoft's Internetwork Packet Exchange and NetBEUI, Novell's Netware Internetwork Packet Exchange, and Sun Microsystems' Network File System. Although some NAS boxes will run a standard operating system like Windows, many NAS devices run their own proprietary operating system. For example, the NAS platforms from NetApp use the company's proprietary Data ONTAP operating system. Management utilities are able to manage heterogeneous multiple NAS boxes as more storage is added to the infrastructure, easing the management burden on storage administrators.
Network-attached storage can be a step toward and included as part of a more sophisticated storage system known as a storage area network (SAN).