Compact Disk

A compact disc or "CD" is a flat round disc used to store data. They are used to store music and other sounds (and sometimes called an "audio CD").

A standard CD-ROM can store up to 700 Megabytes of data. As a comparison a DVD can store about 4700 Megabytes of data.

In order to use a CD-ROM, you need a CD-ROM drive or (now more commonly) a DVD drive that can also read the disk.

CDs come in different formats:

  • CD-ROM - Read Only Memory
  • CD-RW - Read Write
  • CD-R - Recordable

Data is stored on the disk by 'burning' the disk. What actually happens is that a tiny laser beam burns a minute pit into the disk surface, each pit represents a binary bit. The pits are burnt in a spiral as the disk spins around at high speed in the drive.

Challenge see if you can find out one extra fact on this topic that we haven't already told you

Click on this link: Compact Disk


back to glossaryback to glossary