Super Audio CD
Super Audio CD (SACD) is a high-resolution, read-only optical disc for audio storage. Sony and Philips Electronics jointly developed the technology, and publicized it in 1999. It is designated as the Scarlet Book standard. Sony and Philips previously collaborated to define the Compact Disc standard (as well as the S/PDIF digital audio cable specification). SACDs allow greater dynamic range and may hold more playing time than CDs.