It's not a stupid question, and I also regard the entire A3, A30 or whatever model as the "player". The HD DVD drive is the unit in the player where you put the disc. If you open up your player, you can see that it is just like a regular DVD-ROM you will find in computers. This unit has, as I understand it, its own firmware.
If you for instance have problems with your player reading the discs properly, you can change only the drive.