Redundant Array of Independent Disks, or RAID, is a way of storing content on multiple hard disk drives concurrently. A RAID could be software or hardware depending on the drives that are used - physical or logical ones, but what’s common between them is the fact that they all perform as one single unit where data is kept. The biggest advantage of employing a RAID is redundancy because the data on all the drives is identical all of the time, so even in case a drive fails for some reason, the information will still be present on the other drives. The general performance will also improve since the reading and writing processes will be split between a number of drives, so a single one won't be overloaded. There are different kinds of RAIDs where the performance and fault tolerance may vary according to the specific setup - whether your data is written on all drives in real time or it's written on one drive and then mirrored on another, what number of drives are used for the RAID, and so on.
RAID in Cloud Website Hosting
The cutting-edge cloud web hosting platform where all cloud website hosting accounts are created uses super fast SSD drives as opposed to the traditional HDDs, and they function in RAID-Z. With this setup, numerous hard disks operate together and at least a single one is a dedicated parity disk. Basically, when data is written on the other drives, it's cloned on the parity one adding an extra bit. This is done for redundancy as even if some drive fails or falls out of the RAID for some reason, the information can be rebuilt and verified thanks to the parity disk and the data stored on the other ones, so nothing will be lost and there won't be any service interruptions. This is an additional level of security for your info along with the top-notch ZFS file system which uses checksums to guarantee that all data on our servers is undamaged and is not silently corrupted.