How do CAPTCHA look like?

CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) typically appears as distorted text or images that users must identify to prove they are human. Common forms include alphanumeric characters overlaid on a background, images requiring selection (such as identifying all traffic lights), or simple math problems. The design is intentionally challenging for bots but usually manageable for humans. Newer versions may also involve checking a box or sliding a puzzle piece.