To verify that the user is a human and not a bot, a simple test is performed. The user is asked to press and hold a button or key on their keyboard for a specified period. This action requires human dexterity and cognitive ability, making it difficult for automated systems to replicate. Once the user releases the key or button, a reference ID is generated and displayed on the screen. This verification process helps protect websites from spam and malicious activity, ensuring a safer online experience for users.
Source: https://www.sfgate.com/tech/article/mark-zuckerberg-wants-ai-glasses-20798250.php