Mac OS X 10.6: About DVD Player
If your Mac computer has a DVD drive (such as a SuperDrive) or is connected to an external DVD drive, you can use DVD Player to play DVDs on your computer. You can even connect your computer to a television or stereo and use DVD Player to watch or listen to DVDs on your home entertainment system.
You can set System Preferences so that DVD Player opens whenever you insert a DVD.
If your computer supports Apple Remote, you can use Front Row to play DVDs on your computer. You can also use Apple Remote to control DVD Player.