CD writer is a piece of equipment used to record data permanently onto a compact disc. It is an internal or external writable Compact Disc drive that can be attached to a computer. A recorder encodes or burns the data onto a recordable CD-R, DVD-R or DVD+R disc by selectively heating parts of an organic dye layer in the disc with a laser in its write head. This changes the reflectivity of the dye, thereby creating marks that can be read as with the "pits" and "lands" on pressed discs. The process is permanent and the media can be written to only once. CD Writers started at low speeds and are unlikely to exceed the 52x/56x speeds as the drives and media would not be able to work at higher speeds. CD-Recordable (CD-R) and CD-Rewritable (CD-RW) are the two most common types of CDs, which can be written on either once or repeatedly. Copying data to a CD takes just a couple of minutes and can then be used in almost all players instantly.