A DVD burner is a device used to encode or "burn" information onto a blank DVD. A DVD is a form of storage media, 12 cm (4.72 inches) or 8 cm (3.15 inches) across, that can typically hold 4.7 gigabytes (GB) of information. This is enough to hold a three-hour movie at high quality, ten TV episodes, about 75 hours of .MP3 files, or roughly 15 hours of video in the lower-grade .AVI format. The DVD is thought of as the successor to the conventional CD (compact disk), and common formats include DVD-R and DVD-RW, a rewritable version of the DVD.
DVDs are typically quite inexpensive, and they cost even less when bought in bulk. The cost of these storage media has fallen rapidly throughout the late 1990s and early 2000s, and continues to become more affordable as manufacturing costs diminish. The burner allows this storage medium to become even more flexible than before.
Initially, the acronym "DVD" was supposed to stand for digital video disc, but because it can hold any type of data, not just video, members of the inter-corporation DVD Forum refer to it as a digital versatile disc. DVD players became affordable sometime around 1999, as their cost dropped below $300 US Dollars (USD). The DVD burner has always been more expensive, but its price has dropped as well.
The DVD burner has largely displaced its predecessor, the CD burner, especially since prices have fallen to the point that most computer owners can afford them. DVDs and burners are widely used with video, which is storage-hungry in comparison to text and music files.
A major worry for the industry is that the DVD burner might be used widely to pirate copyrighted DVDs. Indeed, many people now download videos using file-sharing programs and then burn them to DVDs. Most commercial discs have special safeguards to discourage their copying, however.
A DVD has a recording layer coated in an organic dye. A DVD burning laser, of higher intensity than a typical DVD reading laser, etches patterns into the dye, allowing the data to be read at a later date. A rewritable DVD uses a special metal alloy instead of a dye. The alloy can be switched back and forth between an amorphous and crystalline phase through the application of a laser, allowing the DVD to be rewritten a substantial number of times. Data quality degrades if the DVD is rewritten excessively, however.