There are two categories of people that buy a home cinema system. Most of them prefer a simple and cheap system that is composed from a DVD player, a regular television and a set of speakers. However, there are also the persons that invest a lot of money and purchase a high end home cinema, including large diagonal plasma or LCD televisions, Blu-ray players, big speakers and a comfortable modern sofa. These are the persons that have expectations and they definitely have to buy a receiver in order to make things look and sound good.
So what is a receiver anyway? Most would say that it is the heart and brains of your home theater. Basically, it collects the audio and video (AV) signals and amplifies them to a desired output source. The receiver is necessary in order to reproduce with high fidelity the surround sound you enjoy at the cinema. On top of this, high end amplifiers include decoding processors like Dolby Digital and are capable of offering a qualitative sound, at the right price of course. Another important feature of the receivers is their connectivity, allowing you to benefit from various input or output sources.
Good receivers cost a lot of money, but they are an essential piece in building your dream home theater, so you must not neglect them. Don't forget that there are digital or analog receivers and it is up to you to make a choice between quality and technology.