Network-attached storage (NAS) systems are generally computing-storage devices that can be accessed over a computer network, rather than directly being connected to the computer (via a computer bus). This was meant to have a storage array device that incorporated a file system and presented either a networked file system protocol such as NFS or CIFS, or else emulated a disk device so that the array could be connected to a storage I/O interconnect to the host.
A network-attached storage (NAS) device is a server that is dedicated to nothing more than file sharing. It does not provide e-mail, authentication or file management. NAS allows more hard disk storage space to be added to a network that already utilises servers without shutting them down for maintenance and upgrades. With a NAS device, the server handles all of the processing of data but a NAS device delivers the data to the user. A NAS device does not need to be located within the server but can exist anywhere in a LAN and can be made up of multiple networked NAS devices.
Network attached storage NAS solutions are designed specifically to serve files that can handle high-bandwidth, and manage file-serving tasks, increasing efficiency. This allows the Network Server to focus on critical business tasks such as application handling and email. It also allows connecting to multiple operating systems and sharing data among disparate clients and servers. | 
