RAID, which stands for Redundant Array of Independent (or inexpensive, depending on who you ask) Disks, is a category of disk drives which utilizes two or more hard drives in order to ensure that data is stored safely.
There are several different levels of RAID, each which have their own specific method of protecting the data stored on each hard drive. Some of the most commonly used are:
RAID 0: This type features data stripping, which spreads parts of a file across multiple drives. This is used to increase performance, but if one drive fails, the data in the array is lost.
RAID 1: This type is used for data mirroring, in which data is written to two drives simultaneously. This ensures that all data is duplicated on both drives, and if one drive fails, the other will still have a backup. This also helps in increasing performance.
RAID 4: This type is similar to RAID 0, with the exception that if there is a disk failure, the data from that drive can be recovered by a replacement disk that is created when a fault is found. However, the creation process of the replacement disk can cause problems, such as performance slow downs.
RAID 5: This is perhaps the most popular type of RAID array. This type features the stripping of RAID 0, as well as error correction, resulting in a combination of excellent performance and fault tolerance.
The use of RAID in personal computers is slowly on the rise. Previously, higher costs of RAID-compatible hard drives made them undesirable to the general public. RAID is used extensively throughout high end computers and in business computing environments; it is slowly finding ground in the home as prices continue to decrease.
The combination of high performance and data protection makes RAID a hard choice to turn down, especially because more and more people are depending on their computer's hard drives to keep important data secure.