Origin
Mini DVD technology, also known as compact DVD (or cDVD), was originally developed for use in hand-held video cameras to improve the cameras' portability. Mini DVD discs are only two-thirds the size of a standard DVD (80 mm vs. 120 mm) and, as a result, can only store about 1.3 gigabytes of data (or about 30 minutes of recording time). Mini DVDs store data in the same format--and players read that data using the same technology--as the full-sized versions.
Composition
DVDs are composed of several layers of polycarbonate plastic, with one layer containing a reflective sheet of aluminum. To put something on the mini DVD, the video, audio or computer data must first be converted into binary code by a computer or recording device. When the DVD is recorded (or "burned"), the DVD burner uses a laser to etch the binary data into the plastic as a series of pits--or bumps, depending on which side of the disc is being viewed--and flat areas.
Playback
When the data is burned onto a mini DVD, it can be read by any DVD player. When the disc is inserted into the player, a spindle is inserted through the middle hole of the DVD; this hole is the same size as the hole on a standard DVD, so the discs are interchangeable. The spindle then spins the disc, and a laser is focused onto the data track; the laser reflects off of the pits and the reflected light is interpreted by a processor as a re-creation of the binary code burned onto the disc. The DVD player decodes the binary language into video, audio or computer data, then feeds it to the attached computer or output device. Since the laser starts at the inside of the mini DVD and reads outward, the physical size of the disc is irrelevant as long as it can hold the intended data.
Tags: audio computer, audio computer data, binary code, burned onto, computer data, video audio