system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does a touch screen work?
gpt
There are different types, but the most common one used today is called the "Capacitive" touch screen. 

The human body is conductive and the skin holds a slight electrical charge. Capacitive touch screens pick up on this charge with multiple sensors placed along the edges of the screen. 

Essentially, you can imagine these sensors as being placed in a grid of columns(on top) and rows(on the sides). Whenever a sensor for a column and a sensor for a row both have a change in voltage, they will overlap at one single point.

you can imagine it like so:
  
           ^        
       | | | | |
      -
    < -    o
      -
      -
      -

The arrows are two sensors which detected a touch at the "o". They then send a signal to the device which uses these as X/Y coordinates. (In this case, it could be (2,3) )