The highest display resolution of the UN40JU6400 is 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 in fact the best display resolution amongst all new TVs.
Amongst similar types of television the worst display resolution is HD Ready.
4K Ultra HD TVs have a resolution of 3840 x 2160 pixels.