system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What exactly makes smartphones screen responsive to touches, swipes, etc?

What's that ingredient that helps interface are fingers so that the smartphone screen recognises the input?
gpt
There are multiple types, but for a common type the simple answer is that your skin conducts a bit of electricity and closes a circuit hidden in the screen. Based on which circuits turn on, it knows where your finger is.