What is RAID discs?

Answer 1

There are no RAID "DISCS". RAID (Redundent Array of Independent Disks) is a method of storing data on separate hard drives in order to either increase data transfer speed or to allow for recovery of data in case of a hard drive failure. There are many different types of RAID configuration which I'm not going to go into here.

Answer--Redundant Array of Independent Discs

Lets start with the basics. R.A.I.D. Redundant Array of Independent Discs. In the old days it also used to mean Redundant Array of Inexpensive Discs. A RAID system is a collection of hard drives joined together using a level definition (see levels below). There are many uses for it. First it can be used to stripe drives together to give more overall access speed (level 0). Second it can be used mirror drives (level 1). Third it can be used to increase uptime of your overall storage by striping drives together and then keeping parity data, if a drive should fail the system keeps operating (level 5). Most people use level 5 for the uptime purposes and its ability to join together 16 drives, giving a large storage block. Read about the levels below and see which one suits you best.