If you want to verify that a person is interacting with the form and that the form is not being programmatically submitted while unattended, you can configure a form to include a CAPTCHA control. The CAPTCHA field available for Unity Forms uses the Google reCAPTCHA service. For more information about this service, see the following:
https://www.google.com/recaptcha/intro/index.html
In order for the CAPTCHA control to be added to a form, a few setup steps are required: