Acronym: Completely Automated Public Turing test to Tell Computers and Humans Apart.

Tests that are easy for a human to pass, but difficult for a computer (thus preventing things like automated signups).

when you're hungover as shit after a spending a night drunk as a skunk

An image with random letters and/or numbers used to prevent spammers from using computer programs to automatically register accounts and/or post/send unwanted advertisements.

that annoying thing with letters and number (e.g. A7FF9YTP) that sucks a lot when you do it wrong cause you have go back and do another one.

A CAPTCHA is a test to see if you are a robot while signing in to sights, posting stuff, etc. For some reason, Internet workers decided that just because a robot can make accounts, post stuff and all that doesn't mean it can tap a ✅ on a box or select all the pictures with traffic lights and all that stuff. No, that's impossible but making users and everything isn't. Of course.

Those really annoying things where you have to find all cars in a picture or type out a phrase like 789obe to prove your not a human

A racist test used to prevent non-humans from entering your website