Right, if you take a normal Audio CD (shop purchased not an MP3 one), and pop it in most CD drives, (be it in the car, home Hi-Fi etc.), you normally just see on the display "Track 1", "Track 2" etc, as obviously normal Audio CD's don't usually contain full track information (although some do).
With the Navigation Pro, it has an internal database of CD's done by a company called Gracenotes, which looks at the CD when it's inserted and compares it's contents and identifier to it's internal database. If it finds a match, then instead of just "CD Track 1", Track 2" etc, it displays the full album Name, track names and also full album artwork for the CD on the nav screen without any intervention from you - it's automatic.