If you've watched many movies on video, you've probably read the words, "This film has been modified from its original version." But how has it been modified? The message that appears at the beginning of video tapes isn't very specific. As it turns out, there are a number of ways video producers modify theatrical films for video release, and elements of these processes have sparked heated debates about maintaining artistic visions.

In this edition of HowStuffWorks, we'll examine the methods and issues involved in formatting movies for videos, DVDs and television. We'll also take a look at the history of film aspect ratios and talk a little bit about the future of video formatting. By the end of this article, you'll be able to watch movies and videos with a whole new understanding of the process of their production!