system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do CAPTCHA's work?

How does typing a few letters distinguish a human from a machine?
gpt
the theory behind it is that a human can decipher the letters while a machine due to it being horrible at recognising jumbled words they can not decipher the message making it impossible for it to get into past the captcha. computers are getting better and better though so captchas are getting harder and harder to decipher by humans.