Optical storage Optical storage Optical storage is the storage of data on an optically readable medium. Data is recorded by making marks in a pattern that can be read back with the aid of light, usually a beam of laser light precisely focused on a spinning optical disc. An older example of optical storage that does not require the use of computers, is microform. There are other means of optically storing data and new methods are in development. An optical disc drive is a device in a computer that can read CD-ROMs or other optical discs, such as DVDs and Blu-ray discs.
Optical disc authoring require writing the entire disc at once, but allow writing of different parts at different times. This allows a user to construct a disc incrementally, as it could be on a rewritable medium like a floppy disk or rewritable CD. However, if the disc is non-rewritable, a given bit can be written only once. Due to this limitation, a non-rewritable disc whose burn failed for any reason cannot be repaired. (Such a disc is colloquially termed a "coaster", a reference to a beverage coaster.) There are many optical disc authoring technologies for optimizing the authoring process and preventing errors. Some