In March 1979, a prototype of a ‘Compact Disc (CD) digital audio system’ was publicly presented and demonstrated to an audience of about 300 journalists at Philips in Eindhoven, The Netherlands. This milestone effectively marked the beginning of the digital entertainment era. In the years to follow, the CD-audio system became an astonishing worldwide success, and was followed by successful derivatives such as CD-ROM, CD-RW, DVD, and recently Blu-ray Disc. Today, around the thirtieth anniversary of the milestone, it is taken for granted that media content is stored and distributed digitally, and the analog era seems long gone. This book retraces the origins of the CD system and the subsequent evolution of digital optical storage, with a focus on the contributions of Philips to this field. The book contains perspectives on the history and evolution of optical storage, along with reproductions of key technical contributions of Philips to the field.