subject: Dvd Storage Requires A Special Recording Machine [print this page] The DVD is the same size as a CD and looks the same. Not considering the appearance, however, each type of disc has a different purpose. There is more than one type of DVD storage that can be provided. It can play music, but, can display the visual as well as the auditory. As in a music video for example, audio and video are played.
The disc with a single-side and layer can store 4.7 GB. The single-sided DVD with a double-layer DVD stores 8.5 to 8.7 GB. A double-sided, single-layer DVD stores 9.4 GB. Finally, the DVD with a double-side and double-layer will hold 17.08 GB. The DVD that is double-layer and double-sided is not seen often.
The DVD as we know it today was not available until after 1995. Four electronics companies participated in its invention. They now come already recorded and manufactured with specialized machinery. The data stored there is stamped on. This type is called a DVD-ROM. They can only be played, but not erased, when someone purchases them. Any data they stored on them cannot be altered.
The newly-purchased recordable DVD-R and DVD+R is made to be recorded by the purchaser. After that initial recording it can only play the data, but, not record over what is on it. DVDs that are recordable, erasable and recordable again are called rewritable, or DVD-RW and DVD plus RW. They are also called DVD-RAM.
Many records need to be kept for a long time, decades or more. Hospital and other medical records are one example. Bank records and tax records are also preserved. DVD storage provides that capability when the more expensive DVD are used for recording the data.
When data is kept in DVD storage it is placed on an AVCHD disc. DVDs manufactured for DVD storage are made to last for an extensive period of time. It is estimated to be between two and fifteen years. Some, such as the M-DISC DVD have an unusual layer added to resist becoming degraded and losing the data that is saved on it. These need a special recorder.
