The 4k is the improvement of the resolution of the image, it is also known as UHD (Ultra High Definition). In the world of technology K corresponds to a thousand. Therefore 4k refers to the 4000 pixels of which different image formats have this resolution. This expression was proposed by the DCI (Digital Cinema Initiatives) for products with more than 4096 pixels in their horizontal length. Pixels are the points that make up an image.
In this innovative video resolution we find 4096 x 2160 pixels. Its frame rate per second is still 24 and its color depth is 8 bits. This is how the film industry defines this format referred to as 4K DCI. There are also 8k and 12k videos.
Since that time, the broadcasting industry has embraced it with different modifications, giving rise to what we know today as UHD. By means of this variant, the 2160 lines are kept horizontal but the vertical lines are reduced to 3860. In this way, it is possible to maintain the 16/9 aspect ratio with which it is already broadcast and avoid the annoying black bands. On the other hand, with the change in resolution we achieve an increase in the depth of the color, allowing us to use 10 or 12-bit videos.
The main advantage of this format is the perfect definition. By counting the images with more pixels, it is achieved that these are more precise allowing to appreciate multiple details. In this way, the user can enjoy these screens at a shorter distance than with a screen with the same diagonal but Full HD resolution. Enlarging pixels on the same screen size causes the pixel density to increase. All this together with the representation of the color makes an image have a greater dynamic range and is much more real.