DVD CDs (0.74 µm for DVD versus 1.6 µm for CD), accounting in part for DVD's increased storage capacity. In comparison, Blu-ray Disc, the successor to the DVD format, uses a wavelength of 405 nm (violet), and one dual-layer disc has a 50 GB storage capacity. Read and write speeds for the first DVD drives and players were 1,385 kB/s (1,353 KiB/s); this speed is usually called "1×". More recent models, at 18× or 20×, have 18 or 20 times that speed. Note that for CD drives, 1× means 153.6 kB/s (150 KiB/s), about one-ninth as swift. DVD-Video is a standard
History of optical storage media History of optical storage media Although research into optical data storage has been ongoing for many decades, the first popular system was the Compact Disc, introduced in 1982, adapted from audio (CD-DA) to data storage (the CD-ROM format) with the 1985 "Yellow Book", and re-adapted as the first mass market optical storage medium with CD-R and CD-RW in 1988. Compact Disc is still the "de facto" standard for audio recordings, although its place for other multimedia recordings and optical data storage has largely been superseded by DVD. DVD (initially an initialism abbreviation of "Digital Video Disc," then modified to "Digital