ATA100, ATA133, SATAI, SATAII, SCSI ===== with each one advancing in speed.
The most commonly used today are the SATAI (150Mbps) and the SATAII (3gbps) drives. RAID is using multiple hard drives to create redundancy (backups) and to help increase performance at the same time. All motherboard support RAID. It is configured through software.
RAID (Redundant Array of Independent Disks). A collection of disk drives that offers increased performance and fault tolerance. There are a number of different RAID levels. The three most commonly used are 0, 1, and 5:
Level 0: striping without parity (spreading out blocks of each file across multiple disks).
Level 1: disk mirroring or duplexing.
Level 2: bit-level striping with parity
Level 3: byte-level striping with dedicated parity. Same as Level 0, but also reserves one dedicated disk for error correction data. It provides good performance and some level of fault tolerance.
Level 4: block-level striping with dedicated parity
Level 5: block-level striping with distributed parity
Level 6: block-level striping with two sets of distributed parity for extra fault tolerance
Level 7: Asynchronous, cached striping with dedicated parity