S/PDIF specifies a Data Link Layer protocol an choice of Physical Layer specifications for carrying digital audio signals between devices and stereo components. The name stands for Sony/Philips Digital Interconnect Format (more commonly known as Sony Philips Digital Interface), the two companies being the primary designers of the S/PDIF format. It is more recently part of a larger collection of standards IEC 60958 (often referred to as AES/EBU), where it is known as IEC 958 type II. S/PDIF is essentially a minor modification of the original AES/EBU standard for consumer use, providing small differences in the protocol and requiring less expensive hardware.