4K Video Resolution-

what is a 4K video?

4K – also known as UHD  -is a picture technology that quadruples the number of pixels found in a full HD picture. These pixels are usually arranged in a 3,840 x 2,160 configuration, compared with the 1920x1080 you get in a full HD TV.
While 4K is the most commonly used name for content and screens that use 3,840 x 2,160 pixels, some brands prefer the term Ultra HD – or UHD for short. 

While confusing, there is actually some logic to the new UHD term. That's because it provides a way of distinguishing between the 3,840 x 2,160 resolution adopted by 16:9-ratio TVs and the slightly different 4096x2160 resolution first introduced in digital cinemas (and actually employed by Sony’s domestic 4K projector range).

However, 4K is used so widely to describe 3,840 x 2,160 displays and content now that the roots of the technical distinction between the 4K and UHD terms have been all but lost outside of the projection world. In other words, for most people the two terms have become interchangeable

Full Aperture 4k	4096 x 3112	12,746,752 pixels
Academy 4k	3656 x 2664	9,739,584 pixels
Digital Cinema 4k	4096 x 1714	7,020,544 pixels
Digital Cinema Aperture 4k	3996 x 2160	8,631,360 pixels

YouTube enabled 4K video support in the middle of 2010. Today, it's the highest resolution format available for consumers and it has great potential! It's quite possible that the demand for this format will increase in near future, specially by digital video data delivery services.