Home theater is a broad term that refers to a system of audio-visual components designed to recreate the experience of being in a movie theater in one's own home. Most home theater systems consist of a large, high quality television set, a surround sound system and several speakers and a DVD player or another device capable of playing movies in high-quality surround sound format.HowStuffWorks: Home Theater: What Do You Need?
Surround Sound
Surround sound is provided by several speakers arranged to the front, rear and sides of the viewer. The audio receiver works by splitting the audio signals into different channels and sending these audio signals to the appropriate speaker, thus creating the feeling that the viewer is "surrounded" by sound and experiencing the sounds much like they would if they were actually in the scene they are watching.HowStuffWorks: How Home Theater Works Surround Sound Basics