disk controller:    1) A component in a PC, workstation or server that controllers mass storage devices. This can be integrated on the main board or as an add-on card. 2) A printed circuit board mounted on a disc or tape drive that controls its internal functions. 3) A component in a storage array that controls mass storage devices, often offering data protection (RAID) and volume management services.

See also: controller, DDF, Disk Data Format