Definition: A technology permitting an optical disc to contain five times as much data as a traditional DVD, which means that a movie stored on a Blu-ray disc can be shown with a sharper, more detailed picture. In 2006 movies began being released on Blu-ray discs, but they can't be played on traditional DVD players. To watch a Blu-ray disc, you'll need either a Blu-ray player or a PlayStation model capable of handling the Blu-ray format.

Also, to get the full benefit of Blu-ray, you'll need to watch the movie on an HDTV with a fairly large screen.