A receiver is the hub for all of the audio/visual elements of your home theater setup. It manages the audio and video inputs from various sources, such as a streaming media device, Blu-ray player or turntable, and sends the signals to your speakers and display. So, a receiver can serve as the center of both your movie and video system. If you are choosing a home audio system, think about getting a receiver for speakers that will also accommodate video.
When choosing your receiver, focus mainly on the sound setup and quality you want. If you want surround sound, you need an A/V receiver with 5.1 channels or more. Fewer channels can handle stereo sound, but not surround. More channels can handle multi-room audio systems. For certain sound systems, you might also want to connect your receiver with a preamp.