The UE48JU6750 has a maximum display resolution of 4K Ultra HD. That's over four times the display resolution of a Full HD television, which is the most frequently found display resolution. 4K Ultra HD TVs have a resolution of 3840 x 2160 pixels.
This TV's display resolution (4K Ultra HD) is actually the best display resolution amongst all comparable spec TVs that were released around the same time as the UE48JU6750.
An HD ready HD type is the worst display resolution across comparable types of TV.
4K Ultra HD TVs have a resolution of 3840 x 2160 pixels.