DVD stands for Digital Video Disk or Digital Versatile Disk. It is the next generation of optical disk storage technology. It is a faster CD that can hold cinema like video better than CD audio.
DVD drive is an optical ROM. The disk is made up of poly carbonate. It is coated with material which will change its reflecting property. When a high intensity laser beam is focused on it. The coating material is highly reflective. The high intensity laser beam forms a tiny pit along a trace represent one and source without pit known land represent zero.
There are various variations of DVD DVD-ROM or DVD-R is physical format and DVD video or DVD audio is application format.
DVDs are the same diameter and thickness as CDs and they are made using some same material and manufacturing method.
Like a CD the data on a DVD is encoded in the form of small bits and bumps in the track of the disk.
There are five recordable version of DVD-ROM.
a. DVD-R for general
b. DVD-R for authoring