The LG 49UB820 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.
This TV's display resolution (4K Ultra HD) is actually the best display resolution across all TVs of a similar spec and age to the 49UB820.
The worst display resolution across comparable types of TV is Not supported.
4K Ultra HD TVs have a resolution of 3840 x 2160 pixels.
Other 4K Ultra HD TVs currently available that you might also want to look at include because of it's better review score, the LG 42UB820, or the Samsung UE48HU7500.