DVD refers to a 12 cm digital disc which can have a variety of options for capacity and use, described below. It achieves a much higher storage capacity than CD by using a shorter wavelength laser beam, smaller pits and narrower track pitch (1). Single-sided and double-sided versions are possible, with one or two layers of information on each side.
The basic pre-recorded DVD which can support DVD-Video and DVD- Audio formatted data. Its storage options are shown in Table App.Y.1.
Table App.Y.1 DVD capacities
|DVD-5||Single-sided, single layer||4.7 gigabytes|
|DVD-9||Single-sided, dual layer||8.5 gigabytes|
|DVD-10||Double-sided, single layer||9.4 gigabytes|
|DVD-14||Double-sided, one single, ...|