external drive - technical definition

Typically refers to a stand-alone magnetic disk or optical disc drive that is housed in its own case and plugs into the computer via a USB cable. Compact external drives, which are designed for transportability, derive their power directly from the USB port (see pocket hard drive). For stationary use, larger external drives plug into a wall outlet.

The term may also refer to external SCSI disks and tapes, which plug into the SCSI controller in the computer and were more common in the 1990s. Contrast with internal drive. See USB drive and portable hard drive.