Definition of - HD TV

HD TV stands for high definition television and is available from digital TV signals and Blu-ray disc players. HD improves on the older analog signal as it comes in a 16:9 theatre style aspect ratio. The resolution of HDTV improves from the old 420 vertical lines and come in 720p, 1080i and 1080p. The numbers equate to the number of vertical lines creating the picture and the letter refers to the type of scan used by the Television to show the picture.
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