Small Computer System Interface (SCSI) is a set of standards for physically connecting and transferring data between computers and peripheral devices.

The physical SCSI interfaces - originally used to attach peripherals like disks, scanners and tape drives - have mostly been superseded by and .

The SCSI command set that was originally defined for (parallel) SCSI buses has been carried forward with minimal change for use with , , Serial Attached SCSI , and other transport layers.