Ultra high-definition video, commonly referred to as 4K video, is a video resolution standard in television and video playback. It has approximately 4,000 horizontal pixels, which creates a resolution that is four times that of high-definition television.
The Consumer Electronics Association defines ultra high-definition televisions as having at least 8 million active pixels and achieving a minimum resolution boundary of 3,840 pixels wide by 2,160 pixels high. Even though many televisions fall below the 4,000-pixel width threshold, the 4K label has become a popular nickname for the resolution standard. Though they were first commercially available in 2003, ultra high-definition televisions and the 4K video format have not yet, as of November 2014, achieved widespread consumer use.