The highest display resolution of the 58PUS6809 is 4K Ultra HD. That's over four times the display resolution of a Full HD TV, which is the most frequently found display resolution. 4K Ultra HD TVs have a resolution of 3840 x 2160 pixels.
This television's display resolution (4K Ultra HD) is in fact the best display resolution across all large TVs that are a comparable age to the 58PUS6809.
A Full HD HD type is the worst display resolution across similar types of television.
4K Ultra HD TVs have a resolution of 3840 x 2160 pixels.
It may also be worth considering one of the alternative 4K Ultra HD TVs currently available including because of it's better review score, the Sony FWD-55X8600, or the Samsung UE55HU8200.