CAPTCHA, reCAPTCHA, and hCAPTCHA help keep bots from spamming your forms or logging in to your WordPress website without permission.
CAPTCHAs can prevent spam submissions on your comment forms, brute force attacks, malware, and other forms of online attacks.
In this way, they can make sure that your WordPress website is safe and secure against some threats. You may also like to see our complete WordPress security guide for more information.