system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How is it that phones differentiate between fingers touching the screen and material objects?

So yeah, in my immense procrastination efforts for my exam, I was sitting with my pen and poking it at my phone. Why is it that when I try to operate my phone with a pen it will not work, but when doing it with my fingers it works seamlessly? How does the phone know that it is human fingers operating the screen and why is that only way the phone can be operated?
gpt
Explanation: Your fingers conduct electricity and are capable of completing an electrical circuit at the point of contact. Certain objects can also do this, but many do not, hence why wearing certain kinds of gloves, for instance, won't manipulate the screen, while others will. The screen is programmed to respond to this completed circuit in certain ways depending on where exactly it's completed, hence how you can select a button on the homepage and have it go to a specific app. The phone isn't doing anything to actively discern a finger from an object; it's just electrical conduction.

Edit: Wording and fleshing out a full explanation.