RAID, which stands for redundant array of inexpensive (or independent) disks, is a disk drive technology that combines multiple disk drives into a single volume. Compared to standard disk drives, RAID gives an advantage of either improved read/write performance, data redundancy, or both.

RAID is accomplished by using three basic technologies, disk striping, mirroring, or parity. These technologies help define the various levels of RAID. Each of the RAID levels will use either one or a combination of these technologies.

RAID can be accomplished using either a dedicated hardware based disk controller, by the operating system, or by a motherboard with RAID software integrated in the BIOS. When using a dedicated hardware controller, the RAID is often referred to as “hardware RAID”. If the RAID array is maintained by an application running in the operating system, it is referred to as “software RAID”. Often times the method of using a motherboard with RAID in the BIOS is called “fake RAID”.