The UE78HU8500 has a maximum display resolution of 4K Ultra HD. That's over four times the display resolution of the most common HD type of Full HD. 4K Ultra HD TVs have a resolution of 3840 x 2160 pixels.
A 4K Ultra HD HD type is actually the best display resolution across all TVs of a similar age and type to the UE78HU8500.
The worst display resolution amongst comparable types of television is Full HD.
4K Ultra HD TVs have a resolution of 3840 x 2160 pixels.