To confirm that the user is indeed human, many websites and services employ a simple yet effective method. This process typically involves pressing or clicking a button on a page, often labeled as “I’m not a robot” or similar. By doing so, the user demonstrates their ability to make intentional decisions and interact with digital interfaces in a way that machines cannot.
When you press this button, you are essentially providing proof that you have read and understood the terms of service or website usage agreement. This helps prevent automated programs, known as bots, from masquerading as humans and attempting to bypass security measures or access restricted content.
Source: https://www.sfchronicle.com/health/article/mammoth-lakes-hantavirus-20257401.php