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.
DVD-RAM The on-disc structure of DVD-RAM is closely related to hard disk and floppy disk technology, as it stores data in concentric tracks. DVD-RAMs can be accessed just like a hard or floppy disk and usually without any special software. DVD-RWs and DVD+RWs, on the other hand, store data in one long spiral track and require special packet reading/writing software to read and write data discs. Like magneto-optical (MO) technologies, DVD-RAM has numerous rectangles on the disc surface that define the boundaries of data sectors. However, DVD-RAM is not MO but a phase transition medium, similar to CD-RW, DVD-RW, or DVD+RW.