In Communications and computing a machine-readable medium (automated data medium) is a medium capable of storing data in a format readable by a mechanical device (rather than human readable).
Examples of machine-readable media include magnetic media such as magnetic disks, cards, tapes, and drums, punched cards and paper tapes, optical discs, barcodes and magnetic ink characters.
ISBN represented as EAN-13 bar code
showing both machine-readable bars and human-readable digits
Common machine-readable technologies include magnetic recording, processing waveforms, and barcodes. Optical character recognition (OCR) can be used to enable machines to read information available to humans. Any information retrievable by any form of energy can be machine-readable.
This article incorporates public domain material from the General Services Administration document "Federal Standard 1037C".