Grip - cddb etc.

Suse 8.0 I am wondering how CDDB works. When ripping does grip have to go to the free cddb database to get track information ? Any info on how this process works would be helpful. I am puzzled as to why track information is not on the cdrom. Background. Grip has worked well in ripping a couple of CDs to Ogg Vorbis format - but only when I am on the net. Brian Marr