CD ripping is often done in order to create original compilations, though is still often used to make an identical copy of another CD.
Most CD players only play CDs which have .wav file format songs on them. As a result of the large size of .wav files, this limited the amount of music that could be stored on the CD.
With CD-R discs, once you have copied the CD, you can no longer edit its contents. On a CD-RW disc, the files can still be changed after the disc is burned, but most CD players do not play CDRW discs.
Itunes and Windows Media Player are free programs used to rip new CDs. However, to convert files from mp3 to .wav or .wav to mp3, you will need to download a second program, like dBPowerAMP or Winamp Media Player.
The future of CD copying is more or less obsolete, as iPods have increasingly replaced CD players. Ripping CDs to put the files onto an iPod, however, is quite common.