Ultra HD TV, also known as 4k or UHD TV, refers to television displays that provide four times the amount of pixels as its predecessor the Full HDTV 1080p format. The 3840 x 2160 lines of resolution in Ultra HD TVs are twice the amount of both vertical and horizontal lines of the 1920 x 1080p format. Therefore, Ultra HD provides 8.3 megapixels compared to the 2.1 megapixels of 1080p.
Ultra HD was defined on Oct. 17, 2012 when the CEA (Consumer Electronics Association) announced the term Ultra HD (Ultra High Definition) would be used for displays with a video resolution of 3840 x 2160 (8.3 megapixels).
Previous HDTV standards typically fall into two lower video resolutions that include 720p and 1080i. But those formats contain either fewer lines of resolution (720p) or interlaced rather than progressive (1080i).
The next jump in video resolution is 8k UHDTV at 7680 x 4320 (33.2 megapixels) which is 16-times the HDTV standard.
4k Ultra HD video is enhanced with High Dynamic Range (HDR), a color specification that requires HDMI 2.0a and adds more color depth and contrast. For home theater applications, HDR is typically produced with either Dolby Vision or HDR10/HDR10+, but is also found in the HLG standard. Learn more about HDR.