Captcha is an acronym for "Completely Automated Public Turing test to tell Computers and Humans Apart." Captchas display distorted versions of the font that most browsers use to display text. Robots are not supposed to be able to identify this distorted pattern of letters.
However, the AI company Vicarious has created an algorithm that can solve CAPTCHA "with greater than 90% accuracy."
Vacarious released the following video as proof: