Video resolution is a measure of quality that refers to the number of pixels or samples used per inch in either height, width, or both dimensions. The higher the pixel count, the better it will look on your screen and video player.
In simple terms, you need more pixels for greater detail because images are made up of tiny dots called "pixels." A lower-resolution image has fewer pixels across an axis, so there's less information available about what those small dots represent - it could be anything from dirt to a car door handle. That's the reason why there are 4k, 6k, even 8k camera drones, each of them services different consumers.
4K resolution refers to a horizontal display resolution of approximately 4,000 pixels. Digital television and digital cinematography commonly use several different 4K resolutions. In television and consumer media, 3840 × 2160 (4K UHD) is the dominant 4K standard, whereas the movie projection industry uses 4096 × 2160.
6K resolution equates to 6144 x 3160 pixels. In contrast, 4K resolution is 3840 x 2160 pixels. This means that on cameras that shoot 6K video you are getting more than a third more resolution.
8K is the next big resolution upgrade for TVs and monitors that could herald a new era of hyperrealistic visuals in movies, games, and television. It also promises to be one of the most demanding, quadrupling the number of pixels of 4K. That will stretch the limits of internet connections for streaming content, and graphics chips in PCs and consoles trying to render games at that resolution.