It is true that Compact discs are miracles of modern technology. They provide hours of entertainment and hold huge amounts of digital information and all on a disc that is only one millimeter thickness. Compact discs were invented in 1980 by a joint task-force of engineers from Philips and Sony Electrical Companies.
Types of Compact Discs
There are two types of Compact Discs are available on the market.
1- CD, DVD-R “CD, DVD – Recordable” cannot be erased or modified in any way once it is recorded.
2- CD, DVD-RW “CD, DVD – ReWritable” are same capacity as a CD-ROM or DVD-ROM. CD, DVD-RW disks can be erased and re-recorded just like a floppy or hard disk.
CDS are read by a CD players red light laser beam hitting the tiny pits and bumps on a CD’s surface. They play from the centre to the edge. The shelf-life of a CD is about 100 years. CDs rotate at a speed of 400 times a minute at the beginning.