How Home Theater Works

Most DVDs are formatted for one or more surround-sound formats and allow the picture to be presented in its original aspect ratio. For example, many DVDs present movies in widescreen format to match the way the movie looked in the theater, but they use a full-screen presentation for TV shows that originally aired that way. See How Video Formatting Works for more details.

Older DVD players have high-quality playback, but they can't record things you watch the way VCRs can. However, several DVD recorders are currently on the market. Of course, a DVD recorder is a little more expensive than a standard DVD player. But if you want to record a lot of shows, a DVD recorder might be worth the price.

Another recording and playback option is a digital video recorder (DVR). Unlike VCRs, DVRs store video in digital form, on a hard drive. Actually, when you hook up a digital video recorder -- such as a TiVo unit -- all programming is recorded on a hard drive, and then sent onto your television set a few seconds later. This means that you can pause a broadcast TV show, then resume watching it where you left off.

These units don't provide the programming -- you have to connect another video source, like a cable outlet or satellite dish. You also have to connect the unit to a phone line -- it makes a daily call to update its programming information. (An exception to this is fiber optic service, which receives information directly through the video connection.) DVRs are a great option for people who want to record and watch a lot of shows. But the space on the hard drive isn't infinite -- on some models, you have to delete shows you have watched to make room for others you want to record.

In addition, several new digital video recording and playback technologies are emerging on the market. The two most prominent formats are Blu-ray and HD-DVD. Both use a blue-violet laser, as opposed to the red laser DVD players use. Blu-ray holds more data but is more expensive than HD-DVD. The jury's still out on which format will end up being the leader in the marketplace.

For more information on DVD players and DVD technology, check out our comprehensive article How DVDs and DVD Players Work. And, for more information on digital video recorders, check out How DVRs Work.

One of the most important components in a home theater system is the speakers. Even with a top-of-the-line DVD player and audio/video receiver, the sound quality will be terrible if you don't have good speakers. In the next section, we'll find out about these essential components.