(Pronounced skuh-zee.) Acronym for Small Computer System Interface. An interface amounting to a complete expansion bus in which one can plug devices such as hard disk drives, CD-ROM drives, scanners, and laser printers. The most common device in use is the hard disk, which contains most of the control circuitry, leaving the interface free to communicate with other peripherals. One can daisy-chain as many as seven devices to a single port. Confusing to consumers is the profusion of standards with their varying combinations of data transfer rates (from 5 to 640 Mbps) and bus widths (8 or 16 bits). Although they continue to play an important role in the high-end hard disk drive market, FireWire (IEEE 1394) and USB 2.0 are increasingly preferred for other types of peripherals, such as digital cameras. See Fast SCSI, Fast/Wide SCSI, SCSI-1, SCSI-2, SCSI-3, Ultra SCSI, Ultra/Wide SSCI, Ultra-3 SCSI, Ultra 320 SCSI, Ultra 640 SCSI.