RAID (redundant array of independent discs) is a concept in storage subsystems that can deliver higher levels of protection against down-time and data loss than conventional disc drives. RAID refers to a drive architecture designed to safeguard critical data through redundancy. In theory, RAID arrays composed of conventional discs can function for hundreds or even thousands of years without losing data because of a disc failure. RAID also offers other benefits: it can improve input/output performance, make servicing simpler and quicker and allow users to fine-tune the drive system to match the needs of specific applications.