no loss in quality, cds jsut hold informatino they dont have certain 'formats' they're like floppy disks but bertter in every way... cept for scratches.

CD's can be formatted several ways. You can make a data disk, like a floppy, but for playing on comsumer players you will record the CD in Audio format. This is a very low-level format for the disk, with only minimal information about where the tracks start. The audio data itself is completely unformatted. It is raw sample data that can be directly converted to a magnetic offset in the speaker. It is the version in iTunes which is compressed and has a loss of quality. The CD will very accurately reproduce the lower-quality of the song in iTunes!

For CD's to work on a standard CD player the format of the music files has to be WAV. The CD will also have to be an audio disk rather than a data disk. Now days some CD players are capable of playing other formats such as MP3. MP3 is high quality and has a far higher compression rate which means you can fit a lot more songs onto a CD when they are in MP3 format as opposed to WAV format. Cosimo: If you create a data CD with WAV files on it a _normal_ audio CD player won't be able to read it. You're right that some CD players can play MP3 data files, and some of those may also play WAV files. As far as compression ratio is concerned; MP3 uses compression and CD doesn't, however you can have compressed WAV files using A-law or u-law compression. If you encode a CD track to MP3 with a bit rate of 256kbps or more, there will be little noticeable degradation in sound quality from the original CD, however any lower bit-rate will degrade the sound noticably. From the point of view of creating an audio CD from audio files on a computer, you can do this from any format (WAV, MP3, WMA, OGG etc) supported by your CD writing software, as this will re-encode the data/audio into the format necessary for the CD to be read in a standard audio CD player.

The audio format on CDs consists of uncompressed 16-bit linear quantized audio samples taken at a rate of 44.1kHz (along with shed loads of synchronisation and error correction data). When you insert an audio CD into a PC using MS Windows, the tracks show up with a .cda extension, however this is a "pseudo" file format, you can't create .cda files. In effect, the audio on a CD is equivalent to uncompressed WAV file with 16 bit linear quantized audio samples at 44.1kHz, but it's not the same. As for Ipod, I believe they use AAC format which is a proprietary Apple compressed format. It is a "lossy" compression algorithm, which means that some of the original audio information will be missing (similar to ATRAC, the Sony compression algorithm used on MiniDiscs). Therefore, if you create an audio CD from tracks bought from Apple, the sounds quality should be no worse since the quality of the AAC tracks is unlikely to be as good as that of a purchased CD. As someone else mentioned though, some CD players will play MP3 files and some (Sony ones) will play ATRAC format files. In either case these are treated as data files so the CD created would be a data CD, not an audio CD, and the CD would not be playable in a standard, hi-fi CD player. Hope this helps. John