RAID is an acronym for Redundant Array of Independent Disks which is used for to solve the problems of large storage of data. RAID is the way of combining several independent and relatively small disks into a single storage of a large size. The disks included into the array are called array members and can be combined into the array in different ways which are known as RAID levels. Network server market as a means of creating large storage at a lower cost and it would take multiple lower cost. RAID arrays appear to the operating system (OS) as a single logical hard disk. RAID internally used the technique of disk mirroring or disk striping which involves partitioning each drive"s storage space into units ranging from a sector as 512 bytes up to several megabytes. To achieve this specialized software and controllers were needed to manage the data being split between the various drives. Eventually the processing power of your standard computer system allowed the features to filter their way into the personal computer market.