Is 4K Ultra HD different than Blu-ray?

A 4K Ultra HD Blu-ray disc has a much higher capacity than a standard Blu-ray disc which allows it to store a movie with Ultra HD resolution. Normal Blu-ray discs look great, but the maximum resolution is 1920 X 1080. A 4K Ultra HD Blu-ray disc has a resolution of 3840 X 2160. That's 4 times the amount of pixels.