How does iTunes recognise a CD?

As the question says, just how does iTunes know what CD you are playing so it can display the title and tracks?

The only reason I'm asking is that I've just put on a Roxette greatest hits CD that I made myself years ago by recording an original and official audio tape of the album into my laptop to .wav files track by track, then writing to CD. iTunes instantly showed all the information when the CD played, even though the tracks cannot possibly be coded in any way, and the quality must be lower than an original CD.

Clever stuff !!

Cheers

Hugh

It looks up the track numbers and times on the Gracenote database, if it finds an exact match, it adds the data automatically

www.gracenote.com

Ahah, simple as that. Thanks very much for the info.

Cheers

Hugh