To ensure the authenticity of online interactions, many websites and services require users to complete a simple human verification process. This typically involves pressing or clicking a button that says “I’m not a bot” in order to confirm you are indeed a human being.
When you press this button, it triggers a security check that verifies your device’s IP address and other identifying factors to ensure you’re a real person rather than an automated program.
Source: https://www.sfgate.com/politics/article/gavin-newsom-on-donald-trump-california-21122416.php