Video CD a few years later) on each side. The Laserdisc provided picture quality nearly double that of VHS tape and analog audio quality far superior to VHS. Philips later teamed up with Sony to develop a new type of disc, the compact disc or CD. Introduced in 1982 in Japan (1983 in the U.S. and Europe), the CD is about in diameter, and is single-sided. The format was initially designed to store digitized sound and proved to be a success in the music industry. A few years later, Philips decided to give CDs the ability to produce video, just like its
Green Book (CD standard) on CD-i tracks, as well as certain specific files that are required to be present in a CD-i compatible disc. The CD-i Ready format is a type of bridge format, also designed by Philips, that defines discs compatible with CD Digital audio players and CD-i players. This format puts CD-i software and data into the pregap of Track 1. The CD-i Bridge format, defined in Philips' White Book, is a transitional format allowing bridge discs to be played both on CD-ROM drives and on CD-i players. Green Book (CD standard) The "Green Book", formally known as the "CD-i Full Functional