What is RAID?

It is an acronym for Redundant Arrays of Inexpensive (or Independent) Disks. It describes the technique of using 2 or more drives to provide the ability to recover when one drive crashes, or to split the load of writing among many disks.

RAID-0 : Striped Disk Array without Fault Tolerance

If you had two drives, everything you wrote to your disk would be split onto two drives, so that each drive only had to write half as much. That makes it take 1/2 the time to write to the drive.

If one drive crashes, you are left with a meaningless half.

Here is a website that gives a great animation of a RAID-0 writing to 4 different disks. Just click this link ( http://www.acnc.com/04_01_00.html )and then click the picture. Notice that when the PC wants to write "ABCD", it writes A to one disk, B to another, C to another and D to the last.

RAID-0: Mirroring and Duplexing

A copy of everything you write to one disk is written to another disk. This will not save any time, but since all the drives can write at once, it shouldn't take any extra time.

If one drive crashes, you are in great shape, because the other disk has a complete copy.

Here is a website that gives a great animation of a RAID-1 writing to 4 different disks. Just click this link ( http://www.acnc.com/04_01_01.html )and then click the picture. Notice that when the PC wants to write "ABCD", it writes A to each disk, then B to each, then C to each and then D to each.

NO RAID

If you only have one disk drive, you have no RAID structure at all.

See webopedia definition: http://www.webopedia.com/TERM/R/RAID.html