A disk array is an enterprise storage system which contains multiple disk drives. It is differentiated from a disk enclosure in that an array has cache and intelligence so that it can perform functions like redundant array of independent disks and virtualization.
Components of a typical disk array include:
Disk array controller
Cache
Disk enclosures
Power supply
Typical disk arrays fall into three categories:
Network attached storage (NAS) arrays:
HP ProLiant Storage Server
Network Appliance Network Appliance Filer
Modular storage area network (SAN) arrays:
HP Storageworks EVA family products
EMC Corporation CLARiiON
HDS Thunder, Lightning and TagmaStore USP family products
Xiotech Magnitude 3D
Monolithic storage area network (SAN) arrays:
EMC Corporation Symmetrix
HP HP XP