Redundant array of independent disks (RAID),

Definition of Redundant array of independent disks (RAID):

1. Data backup scheme in which a single large (and expensive) hard disk is replaced by two or more smaller disks. Each of these disks (1) has a separate controller, (2) works independently of others, and can (3) automatically take over the functions of any failed disk. RAID may be implemented in any one of several techniques called Levels. Originally called Redundant Array of Inexpensive Disks.