reCAPTCHA
Updated: 09/12/2023 by Computer Hope
A CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) that not only helps protect a site from bots or other scripts, but also helps read books. With a reCAPTCHA, one word is generated by the script and the other is a scanned word that an OCR (Optical Character Reader) program didn't understand. The idea is that if a user successfully understands one of the words the other word is also correct.
The picture shows a reCAPTCHA showing "were" and "tattoos" as words that need to be entered. reCAPTCHA has no real way of knowing what word is generated and what word is the scanned word.