What Is 4K? A Basic Definition


Apr 7, 2015
What happened was that the TV industry was supposed to release a 4K format: a real 4K format, with 4096 pixels horizontal resolution like the DCI standard.
This got a lot of interest in the enthusiast press.
Then the industry's standards body changed its mind, to instead double the resolution from Full HD.
But enthusiasts had followed the development... and to make it clear for them that the new "Ultra HD" format was what had come out of the "4K" development, some TV manufacturers, first among them being Sony, started to market their Ultra HD televisions as "4K".

The monikers "4K UHD" and "4K/UHD" came about as a way to avoid confusion between real 4K and UltraHD.

Note also that there has never been any similar conflation between the DCI standard "2K" and the TV standard "Full HD" ... or at least not before "4K UHD" happened.

It could also be discussed whether computer screens should adopt marketing terms used to sell televisions.
Real computer screens with an actual horizontal video resolution of 4096 pixels do also exist, e.g. in 21.5" iMacs (last Intel based), and some monitors from Eizo among others.