Optical storages can basically be defined as the storage of information on readable mediums that are optically designed. The principle behind is that data is recorded, or rather inserted into the optical mediums by creating patterns that can be read back with the help of light beams. Usually, it is precisely a stray of laser light concentered on a gyrating optical type of a disc. With this, it provides densities of recording starting from 107 bits / cm2 and beyond. Optical discs offer immense recording strengths that are capable of supporting erasable/rewritable, write-once and read-only modes of data storage. The principle behind is that information is pre-recorded on master disks that are afterward used as a stamper to convey the brocaded patterns to plastic substrates for accurate inexpensive and rapid reproduction.
This then makes it possible for the optical disks to accommodate not only media files, movies, music, and videos, but also catalogs, software, and other large database files. It is because the media provides room for prerecorded information and write, read and erase operations on a similar platter hence offering opportunities for more significant applications that have here often been unimaginable.
Tracks are the locations where information is recorded on both optical and magnetic disks. They are partitioned circularly from the disk surface towards the disk center with the last track being some small distance away from the center of the disk. They all bare an annulus width and a guard bandwidth that’s located between the adjacent tracks which also bare a considerable width.
Between the tracks bares a center-to-center distance known as the track-pitch. This track-pitch differs regarding the different types of magnetic disks that are present. Tracks are mainly fictitious since they literally can’t be visualized and also because there’s no independent existence beyond the pattern of inscribed marks that may be attributed to them.
In optical data storages, tracks are further divided into smaller particular segments known as sectors. Sectors are intended for the storage of single data blocks that are either 512 or 1024 bytes. Sectors are accompanied by header information which holds information that identifies each sector.
Optical disks incorporate the technology of directing laser beams used by the read-and-write heads to their pre-recorded marks to identify the information locations so that they can easily be read. These are better identified on the magneto-optical disks and pre-grooved WORM (write once, read many).