Different RAID levels perform in different ways. It's basically a way to increase performance, data recovery, data redundancy and data integrity by implementing a level of RAID for 2 or more alike hard drives.
There are many different RAID levels. There's RAID 0, 1, 0+1, 2, 3, 4, 5, 6, 7, 10, 53. All of these levels require a different amount of drives and perform in very different ways.
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