With 4K TV, images appear crisper and more defined than you’ve ever seen before because it has four times the pixels of a 1080p HDTV. That’s a big difference. A difference of 8 million pixels. An HDTV screen is made up of a grid that is 1,080 rows high and 1,920 columns wide. The 4K grid doubles both the height and width – making it about 4,000 pixels wide, thus the name 4K.
You may also hear 4K referred to as 4K Ultra HDTV, Ultra High Definition (UHD) or Ultra HD. While the terms are often used interchangeably, UHD is actually an all-encompassing term that refers to any TV resolution with more pixels than HDTV. So, while 4K TVs are UHD, not all UHD TVs are necessarily 4K.