Consider for a moment, your smartphone’s screen. First of all it has a resolution of, let’s say, 1920×1080. That’s maybe about 260 pixels per square inch. That means in a space of about 3″ x 4″, give or take, it manages to fit TWO MILLION little switches that let a dot turn completely opaque or completely transparent, or up to 254 levels in between. The distance between each dot is .003 inch, or give or take the width of a human hair.
Then wrap your head around the fact that the glass plate on the front of your phone can detect varying levels of pressure through detecting electrical inductance with a level of precision that lets you distinguish between a yellow candy and a red one. Don’t forget there’s a light bulb in there that provides even illumination over the whole screen even though it’s about a millimeter thick and uses a ridiculously small amount of power.
The computer behind your smartphone’s screen is smart enough to look in more than one place at the same time, and to use weighted averaging to figure out which exact point you want when your finger covers about about .75 square inches of space.
Think about that the next time you’re looking at cat pictures on the internet.