This plan covers:
UHD (Ultra high-definition) monitors have a native resolution of 3840x2160. Although UHD is commonly used along with the term "4K", it is not technically 4K and falls short of the 4096x2160 resolution.
UHD is referred to as "4K" by monitor and TV manufacturers to simplify this definition because full 4K resolutions are only used in cinema and film. The difference between UHD and 4K is only 256 pixels horizontally, and the vast majority of users will find this negligible towards the overall viewing experience.