Firstly, for the CD/DVD manufacture and production a glass master is created from the data. A glass disc is used. This disc is coated with a special photo sensitive layer. The digital data are embedded on the disc using o high laser beam. The laser is controlled by a computer which is also responsible for the accurate digital data’s transfer. If for any reason any error occurs during the procedure the recording is automatic canceled. And the end of the process all the digital data have been imprinted on the stamper. This data have the form of track pitches and data pits. Finally they are nickel plated in order make the surface more durable during the pressing procedure.