system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:How does a modern touchscreen actually works?
gpt
There are actually several types of touchscreens in use today, but most fall into one of two categories; capacitive or resistive. 

Capacitive touchscreens are what you see in your phone, tablet, and MP3 players. These are glass covered with a thin coat of a transparent, conductive material. When the human body part (I won't judge) touches this coating, the bodies own capacitive properties change the capacity of the screen at X and Y coordinates. The phone reads the change at those coordinates and tells the software. 

Resistive touchscreens are similar, but have two films that are separated by a gap. When you press against the screen, it compresses and those two films touch at X and Y, the hardware reads it and it's off again.


Resistive are much more resilient and you can use them through materials such as gloves, so you're likely to see them in places where they're going to get a LOT of use (factories, hospitals, restaurants), but they wear out faster and are generally less precise.

Capacitive are pretty much the exact opposite.


tl;dr They make an electrical contact at point x,y on the screen and the hardware tells the software.