CD-R Full Form

Prerequisite – Compact Disk (CD)
CD-R stands for Compact Disc – Recordable. It is a digital optical disc storage format which was introduces in 1988. CD-R is such type of compact disc that can be written only once. It can be read many times. It is made of a reflective metal disk with a layer of green or opaque bye on top. It is a blank CD in which data can be stored once and after storing data it is converted into CD-ROM.
CD-R disks can be read by most plain CD readers. It can also be read by CD readers manufactured prior to the introduction of CD-R.

History :
CD-R was initially called CD-WO (Compact Disk – Write Once). It was first developed by Philips and Sony in 1988. The specification of CD-R were published in Orange Book in the same year. Later on in 1990 it was completely in market.

Writing to a CD-R :

  • A single tracks runs in spiral pattern from the center of the disc to the side.
  • A high powered laser is shone onto CD-R, changing the transparency of the dye above. The transparent represents the ones and opaque represents zero.
  • The disc Continues to spin and the laser follows the track. It puts the binary data onto CD-R in a spiral track.
  • Finally the data has been written.

Reading from a CD-R :

  • A single track runs in spiral pattern from the center of the disc to the outside.
  • On the surface of the disk a low-powered laser is shone and the reflection is captured in a photodiode sensor. The opaque dye will reflect differently to the transparent dye meaning it can tell the difference between one and zero.
  • The disc continues to spin and the laser follows the track.
  • The binary data are put together and the CD-R has been read.

Advantages :

  • It is less costly.
  • It can be read by any CD player.

Disadvantages :

  • Seek time in CD-R is slow.
  • Data degrades with time.
  • Data can not be written over in CD-R.

Attention reader! Don’t stop learning now. Get hold of all the important CS Theory concepts for SDE interviews with the CS Theory Course at a student-friendly price and become industry ready.

My Personal Notes arrow_drop_up

Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using or mail your article to See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.