OpenELEC is an embedded operating system built specifically to run XBMC, the open source entertainment media hub. The idea behind OpenELEC is to allow people to use their Home Theatre PC (HTPC) like any other device you might have attached to your TV, like a DVD player or Sky box.
But before continuing with OpenELEC i do a step back and say a few words about XBMC.
Xbox Media Center (XBMC) is an open source program created for the Xbox and now available on xbmc.org for Mac, Windows, Linux, Android, Apple TV and Xbox. On all platforms other than Xbox, XBMC acts as an application, possibly launched at boot time or later.
XBMC can play most formats of audio/video, and if there is an internet connection it’s able to use network services, such as getting movie and album reviews, or view movies in streaming.