This computer test determines who the user of the system is – a person or a computer.
If the threshold value is exceeded, for example, the number of requests per second is comfortable for the site, the protection is activated and the user needs to enter information from CAPTCHA to confirm that he or she is not involved in the botnet network, and only then access to the site will be allowed.
After confirmation, the user is entered into the Allow List and is no longer checked.