SCSI connector is used to connect computer parts that use a system called SCSI to communicate with each other. Generally, two connectors, designated male and female, plug together to form a connection which allows two components, such as a computer and a disk drive, to communicate with each other. SCSI connectors can be electrical connectors or optical connectors. There have been a large variety of SCSI connectors in use at one time or another in the computer industry. Twenty-five years of evolution and three major revisions of the standards resulted in requirements for Parallel SCSI connectors that could handle an 8, 16 or 32 bit wide bus running at 5, 10 or 20 megatransfer/s, with conventional or differential signaling. Serial SCSI added another three transport types, each with one or more connector types. Manufacturers have frequently chosen connectors based on factors of size, cost, or convenience at the expense of compatibility.
SCSI often makes use of cables to connect devices together; in a typical example, a socket on a computer motherboard would have one end of a cable plugged into it, while the other end of the cable plugged into a disk drive or other device. This would mean that four connectors were involved in wiring the disk drive and computer together: the connector on the motherboard, the connectors at each end of the cable, and the connector on the disk drive. It is sometimes possible to have cables which have different types of connectors on them, and some cables can have as many as 16 connectors (allowing 16 devices to be wired together). Some types of connectors are typically used inside a computer or disk drive case, while others are used to connect a computer to a separate device such as a scanner or external disk drive.