4K refers to one of two high-definition resolutions: 3840 x 2160 pixels or 4096 x 2160 pixels. 4K is four times the pixel resolution, or twice the line resolution (2160p), of 1080p (1920 x 1080 pixels).

The other high definition resolutions used are 720p and 1080i. These are the resolutions most commonly used in larger screen televisions to create images with more detail.

What makes 4K resolution so special is that, when used on increasingly larger TV screens and video projectors, it produces much more detailed images with fewer pixels than 1080p. 1080p looks great up to about 65 inches and can still look good on larger screen sizes, but as screen sizes increase, 4K can deliver an even better picture.

The increasing availability of 4K provides consumers with a much improved video image for larger screen applications, and can significantly reduce the ability of viewers to see visible pixel structures on the screen unless you get extremely close. This means even smoother edges and depth. Combined with faster screen refresh rates, 4K has the potential to deliver nearly 3D depth without the need for glasses.