4K UHD discs are the newest format of physical media and offer 4K ultra high definition playback. 4K UHD discs require a 4K UHD compatible player (4K UHD discs do not play in normal Blu-ray players) and 4K compatible display, preferably with HDR (high dynamic range). Unlike the DVD and Blu-ray formats, 4K UHD discs do not have any region coding.