Redundant Array of Independent Disks, or RAID, is a method of keeping content on multiple hard drives concurrently. A RAID can be software or hardware based on the HDDs that are used - physical or logical ones, still what is common between them is that they all work as one single unit where information is stored. The key advantage of employing a RAID is redundancy as the info on all the drives will be the same at all times, so even if one of the drives fails for whatever reason, the info will still be available on the other drives. The general performance is enhanced as well because the reading and writing processes can be split between a number of drives, so a single one will never be overloaded. There're different kinds of RAIDs where the effectiveness and fault tolerance may differ based on the specific setup - whether your data is written on all drives real-time or it's written on one drive and after that mirrored on another, what number of drives are used for the RAID, and many others.
RAID in Hosting
The revolutionary cloud hosting platform where all hosting accounts are created employs fast NVMe drives rather than the traditional HDDs, and they work in RAID-Z. With this setup, multiple hard disk drives operate together and at least one is a dedicated parity disk. Simply put, when data is written on the other drives, it is duplicated on the parity one adding an extra bit. This is performed for redundancy as even in case a drive fails or falls out of the RAID for some reason, the data can be rebuilt and verified thanks to the parity disk and the data stored on the other ones, thus nothing will be lost and there won't be any service disturbances. This is an additional level of protection for your information along with the advanced ZFS file system that uses checksums to guarantee that all of the data on our servers is intact and is not silently corrupted.