If you want to transfer a CD onto your iPod, computer, or cell phone, you can always rip the disc to MP3 and reasonably expect it to play on all of your devices. But things aren't quite as simple if you want to do the same thing with a DVD.
Digital video files are complicated, and they come in thousands of varieties. The devices that play digital video are equally complex. A video that plays fine on your computer, may not play on your iPod or mobile phone.
There's no simple solution for making video formats easy to deal with. But with any luck, by the end of this tutorial you'll have a better understanding of how digital video formats work and why they can be so fickle.