What is 4k Ultra HD TV?

Sony-XBR65X850F-65-Inch-4K-Ultra-HD-Smart-LED-TV-720px
Sony XBR65X850F 65-Inch 4K Ultra HD Smart LED TV

4k TV, also known as Ultra HD or UHD TV, refers to television displays that provide 4-times the amount of pixels as its predecessor the Full HDTV 1080p format. The 3840 x 2160 lines of resolution in 4k 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. See 4k TVs on Amazon

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.

SD-HD-UHD-comparison

4k Ultra HD video can be enhanced with High Dynamic Range (HDR), a color specification that requires HDMI 2.0a and adds more color depth and contrast by expanding bit-depth in video on disc and digital. For home theater applications, HDR is typically produced with either Dolby Vision or HDR10/HDR10+, but is also found in the HLG standard in live broadcasts. Learn more about HDR.

Also Read:
What is 4k Ultra HD resolution?
Is 4k resolution the same as 2160p?
What is HDR?
What is 8k Ultra HD TV?