A 4K television has four times the number of pixels as Full HD and is the only way to truly experience films the way their makers designed them to be seen, reproducing all the subtle detail and texture of the original image with an intense depth that draws you into the picture.
The term '4K' refers to a TV or monitor that has a horizontal resolution of approximately 4,000 pixels.
This is also commonly referred to as 'Ultra High Definition' (UHD), which is used for displays of at least 3840px x 2160px.
A comparison of different display resolutions is below:
Please note that a 4K unit is best experienced when displaying the highest quality content possible.
It may not drastically improve the quality of DVDs or Standard Definition TV as compared to viewing them on a lower-resolution display.
When viewing these channels, while still producing excellent picture quality, your TV must stretch or "scale" the image to fill its native 4K resolution.
Scaling allows the source content to fill the screen and produce an excellent picture, but it can't significantly improve the quality present in the source material.
4K is still an emerging standard; however, as time goes by, more content will be able to leverage the full capabilities of your TV.