RAID, now known as the Redundant Array of Independent Disks, was previously known as the Redundant Array of Inexpensive Disks. However, hard disk manufacturers probably thought of getting the conception of inexpensive out of the mind of consumers, hence changing the full form to Redundant Array of Independent Disks. Now, let us try to reason as to why was RAID implemented and hence, try to understand the importance of getting RAID levels explained. The term was first coined and defined by David A. Patterson, Garth A. Gibson, and Randy Katz, at the University of California, in 1987. The reason was simple. To combine multiple hard drives to provide high performance.