At its most basic, a media-center PC is a home computer an A/V receiver combined. It has entertainment-related upgrades that make it a suitable centerpiece for a home theater. Most media-center PCs have progressive-scan DVD playback, over-the-air HDTV support, surround-sound inputs and quieter operation (some use fanless cooling systems). In a single CPU unit, you have a range of functions that encompasses pretty much every aspect of digital media, including: