You’re trying to purchase an item or log into an account. You enter your credentials, but before you proceed, you need to prove that you’re a human being. Tick the box marked “I’m not a robot”. You can see a blurred image with skewed digits that you need to decipher. These are CAPTCHAs, and while they can be a nuisance, they’re necessary.
Right? What are CAPTCHAs and how do they work? How are they different from reCAPTCHAs? And why are many of them so difficult?