The difference between 1080p, 1440p, and 4K monitors lies primarily in the number of pixels and the refresh rate. While 1440p monitors have more than 1.5 times as many pixels as their 1080p ...

That’s why when you buy a TV you’ll see it advertised as supporting 4K, or on smaller screens, 1080p, and similar. Pixels are the building blocks for every display you’ve ever seen.