By distinguishing human and computer bot, Captcha eliminates all security threats which come from malicious and automated programs. The app offers an additional security layer to your site by securely protecting your site during registration/login process and making your site no longer vulnerable to spam. Captcha app provides you full control to customize the way you want Captcha works on your site using default Captcha (letters & numbers), QR Code, or reCaptcha (Checkbox captcha offers by Google).