The UE48JS8502 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 common display resolution. 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 across all new televisions.
Across comparable types of TV the worst display resolution is HD Ready.
4K Ultra HD TVs have a resolution of 3840 x 2160 pixels.
There are a number of other 4K Ultra HD TVs currently available that you might want to look at including the Samsung UE49KS7500 (£970.00) which has a better Rating; or the Samsung UE49KU6509 which is cheaper.