Small Computer Systems Interface - SCSI
Its anything but for small, personal computers. SCSI allows a person to extend the capabilities of their computer by adding peripherals to it in the form of DVD/CD players, scanners, and others, but most often disks. As such it has been for workstations and servers since SATA came out. SCSI devices are more expensive and we now mostly only use it to manage drives (SATA or SAS) in enclosures via iSCSI.
Since parallel SCSI is dead, we will confine ourselves to iSCSI.