CD Burners and DVD Burners

   A CD burner is the informal name for a CD recorder. It's device that can record data to a compact disc. CD-Recordable (CD-R) and CD-Rewritable (CD-RW) are the two most common types of drives that can write CDs, either once (in the case of CD-R) or repeatedly (in the case of CD-RW).

DVD Burner

DVD is an abbreviation for digital versatile disk. It is a disk format similar to a compact disk (CD) but can contain much more data. It was introduced in 1996. DVD disks are the same 120mm diameter as CDs with potential capacities of up to 4.7 gigabytes for a single-sided single-layer disk.

The technology involved in DVD storage is similar to that in compact disks, but more precise. The extra capacity is achieved in a number of ways. The tracks on a DVD are closer and the pits are smaller, allowing more pits per unit area. The key to this was the use of a shorter wavelength laser (typically 635 or 650nm in the red region for DVDs as opposed to 780 nm in the infrared for CDs). Moreover, a DVD can have two layers on the same side of the disk. The top layer is translucent and the bottom layer opaque. Data can be read from either layer by refocusing the laser. In addition DVDs may be double-sided. DVD formats also have a more efficient error-correction system. The potential capacity of a double-sided double-layer DVD is up to 17 gigabytes.