DVD-ROM

Disk format for storing digital information, the DVD equivalent of CD-ROM. Launched in 1997, DVD-ROM disks can store up to 17 gigabytes of data, compared to only 700 megabytes on a CD-ROM. DVD-ROM drives, which are also able to read CD-ROM disks, have a much faster speed of data transfer than CD-ROM drives (a 16× DVD-ROM drive is the equivalent of a 144× CD-ROM drive, with a data transfer rate of 177.28 megabits per second).

As with CD-ROM, there are recordable versions of DVD-ROM, where DVD-R and DVD+R disks can be written to once only, and DVD-RAM, DVD-RW, and DVD+RW can be overwritten. The three rewritable formats are not fully compatible with each other, although ‘DVD Multi’ drives can read from and record to disks in the DVD-R, DVD-RW, and DVD-RAM formats. ‘Super combo’ drives can handle DVD-R, DVD-RW, DVD+R, and DVD+RW disks, while ‘super multi’ drives can read from and write to disks in all five recordable formats.

The two most likely successors to the original format are Blu-ray and HD DVD, both of which were available by 2006. These formats promise re-recordable capacities in excess of 50 gigabytes. Developments with holographic versatile disc (HVD) suggest a potential capacity of 1 terabyte (1,024 gigabytes) and access speeds in excess of 40 times that of a conventional DVD.