What Is 4K?

4K has 4 times the number of pixels as 1080p. 4K referred to 4,000 pixels of horizontal resolution for digital cinemas . 4K =4096 x 2160 or 8.8 megapixels. 4K related to HDMI refers to 3840 x 2160 or 8.3 megapixels that is 4 times the 1920 x 1080 or 2.1 megapixel HDTV standards. 4K Extenders ,  4k Switchers