movie from dvd

Once you've attached your external drive to your Mac, you can use it in exactly the same way as a built-in optical drive: simply insert the DVD or CD into the SuperDrive, and the relevant media-playing app should launch automatically.

The easiest way to play your iMovie created movie is to share the project as a file to your desktop, where you can play it on QuickTimePlayer.

To play a movie on a DVD player you would need to have the movie burned to a DVD disk. Then you insert the disk into the player. The disk icon will appear on your desktop and you can then click on it to play it on your Mac's DVD Player app.

If the above does not cover your situation, post back with some more details as to what stage you are in the movie creation process.

-- Rich