If you’ve spent any time online, you’ve probably been confronted with a pop-up asking to confirm that you’re not a robot. The security prompt, designed to check if you’re a real person, often appears when you're trying to login to an online account.

Sometimes tapping on the “I’m Not A Robot” button isn’t enough, and you’ll be quizzed with a grid of 3x3 pictures ans asked to identify the stairs, bikes, motorcycles, school buses, and more. Other times, you’ll be shown manipulated text that you need to decipher to type the letters and numbers.

But what is all of this for? And what happens when you tick the “I’m Not A Robot” button?

This security method is known as a CAPTCHA, which stands for Completely Automated Public Turing test to tell Computers and Humans Apart. The Turing Test, originally named the Imitation Game, was created by British computer scientist Alan Turing in the 1950s and is designed to put Artificial Intelligence to the test and determine whether it’s indistinguishable from a human min