4K represents a number 4 kilo count of pixels measured in pixels per inch (PPI ) in one chip that has 3840 x 2160 ( H:V ) pixels arrangement. That is the screen ratio between max. signal to smallest part. It is just rounded to 4000 to easily recognize instead of 3840 and now called 4K.
Resolution is a layman's term like " display of signal" or smallest measurement capable of.
Your idea is added.
It’s just 1080p (1920 x 1080) doubled in both x and y. I guess some marketeer figured out that the number is bigger when you use the horizontal number (ish) instead of the vertical (2160p).
If you want to be picky, I would call it a format. But this Wikipedia article seems happy with the word resolution.
Then there’s the question of whether 4K is 4000 or 4096. 😀
There are a number of different resolutions that are labeled "4K". Most don't actually exceed 4 thousand pixels on the X axis. The generally accepted range runs from 3840 to 4096. Most of them use 2160 on the Y axis.
In the world of television format here in the USA we followed the NTSC format but discussed here - format is the way of arrangement of pixels in the horizontal and vertical arrays and no connection to resolution. Then why the seller of TV insist saying " this new tv has 4K resolutions " , because $$$ is the main reason to entice the innocent buyer.
edroksense North America is using ATSC 1.0, and is slowly rolling out ATSC 3.0 (which supports 4K broadcasting). NTSC is the old analog broadcasting standard. We have been fully digital for about 15 years or so now.
Even for SD TV (480i/480p), the digital horizontal resolution could vary. DVD is 720. When I had a cable box with a diagnostics page that showed the resolution of the channel, I would see 640, 512, and even 320.
Yes, most of my DVD rips show as 720x480. Even widescreen (16x9) content still has a resolution of 720x480. Most Blu Rays will be 1920x1080. VHS tape had a max resolution around 240-320, and Super VHS was good for 525, which equaled the best NTSC broadcast signal.
