Definition: A technology that became obsolete in 2008. HD here stands for high definition, and movies began being released on HD DVDs in 2006. These movies had a sharper, more detailed picture than those on traditional DVDs, and the video and audio quality of HD DVD was about the same as that of Blu-ray. But HD DVD and Blu-ray were incompatible with each other, and Blu-ray drove HD DVD out of the marketplace.


