RD44

I have been copying some of my vinyl lps onto a cd hard disk recorder,then copying from the recorder to an audio cd-rw. In 4 out of 5 cases when I imported the cds into iTunes the data was recognised and the artist,album and track titles inserted automatically. How is this possible? As far as I can see the only information available is the number of tracks and track times. Any enlightenment would be appreciated. Many thanks