Can't play a movie on DVD with QuickTime

I can't play a movie on a DVD with QuickTime. With the player open, when I go to File and then Open, I get the two Video and Audio folders on the DVD itself! The Apple Quicktime guide says of how to play video:

"To open a movie on your hard disk, a CD, or a DVD, do one of the following:
1) In the Finder (or Windows Explorer), double-click the file or drag it to the QuickTime Player application icon.
2)Choose File > Open and select the file."

Firstly, if I double click on the DVD drive in Windows Explorer, it'll open the DVD with my default player (not Quicktime). Secondly what is the 'QuickTime Player application icon?
Thanks, Trickyf