Network attached storage (NAS) allows using TCP/IP network to
backup files. This enables multiple servers in IDC to share the
same storage for backup at once, which minimizes overhead by
centrally managing hard disks. NAS is scalable, high performance
network solution. The main advantage is more hard disk storage
space added to a network that already utilizes servers without
shutting them down for maintenance and upgrades.
"Please note that NAS are not just common in IDC or offices but
you can use it for file sharing and backup at home..."