system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Is there a reason or purpose for having fingerprints?
gpt
All those grooves and ridges help our fingers achieve a better grip. It's as simple as that, really.

As an example, take a cellphone and place it screen-side down on the back of your hand and then slowly rotate your wrist. You should find that fairly quickly the phone slides off.

Now take the same phone and place it in the same way on your fingertips. This time you should be able to rotate your hand by well over 45 degrees before it starts to slip.

TLDR: fingerprints = friction.