4K refers to high definition resolution of 3840 x 2160 pixels. 4K (2160p) is twice the line resolution of 1080p (1920 x 1080 pixels) and is about 8.5 megapixels. It greatly improves video display image for larger screen applications, and increases the clarity and definition of a video image. This means even smoother edges and depth. When combined with faster screen refresh rates, 4K has the potential to deliver almost as much depth as 3D but without the need for glasses.