Woman sitting in front of a TV with a logo reading '4K Ultra HD' on the screen
(Image credit: Getty)

4K refers to super-sharp display and video technology where the resolution is roughly 4,000 pixels wide. Detail is the whole point of 4K – most of the time, you won’t be able to see the pixels in a 4K display, so everything looks natural and sharp. It’s great for photos, videos and gaming for this reason, but actually it’s superior for just about everything – it’s nicer when text looks smoother on a computer, for example.

The vast majority of the time, 4K refers to a specific resolution of 3840 x 2160 (which is also known as ‘Ultra HD’) – this is the resolution of all 4K TVs and 4K video streams from the likes of Netflix or YouTube. Some cameras record in what’s often known as ‘Cinema 4K’, which is a resolution of 4096 x 2160. You may find that some computer monitors refer to themselves as 4K, and will have a horizontal resolution around 4,000 pixels, but have a different height to the resolutions mentioned above, such as ultra-wide monitors. The width is what makes something 4K or not.

You’ll mostly see 4K referred to in TVs of 40 inches and above, in computer and laptop monitors, on video streaming services, and in video recording on cameras or phones.

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