Home theater is difficult to define — it’s really just a vague term for a particular approach to home entertainment. Generally speaking, a home theater system is a combination of electronic components designed to recreate the experience of watching a movie in a theater. When you watch a movie on a home theater system, you are more immersed in the experience than when you watch one on an ordinary television.

To build a home theater, then, you need to recreate these elements. At the bare minimum, you need:

• A large-screen television or a Projector with the screen size depending upon room size.
• At least 5.1or 5.1.2 or 7.1 or 7.1.2 speakers setup as per the room
• Equipment for splitting up the surround-sound signal & the Video and sending it to the speakers & the Television or projector ie the Amplifier or AVR  And, of course, you’ll need a room where you can arrange all this stuff.