Google reCAPTCHA is a widely used security service that protects websites from spam and abuse by verifying that a user is human and not a bot. When integrated into a website, the reCAPTCHA script runs in the background, analyzing user behavior patterns and interactions on the page. It employs advanced risk analysis engines and adaptive challenges to distinguish legitimate users from automated software. This analysis helps prevent various forms of abuse, such as fake registrations, credential stuffing, spam comments, and fraudulent transactions, without significantly interrupting the user experience. Depending on the detected risk level, it may present an invisible challenge, an 'I'm not a robot' checkbox, or more complex image-based puzzles.