The Captcha facility is inbuilt in the Directory theme that the users can configure to protect their forms from malicious registrations and activities. There are many machines that run codes that will access website and register on it and perform malicious actions that may cause serious harm to your site.
This harm can sometimes be so serious that the entire site can be made unavailable by overloading the server with requests. Therefore, CAPTCHA is used to tell whether its the human or the machine performing the action on the website.
CAPTCHA stands for Completely Automated Public Turing Test to Tell Computers and Human Apart. This facility comes inbuilt in the Tevolution plugin. To activate it navigate to Dashboard >> Tevolution >> Settings >> General Settings >> Captcha and fill the following form to activate it.
Configuring the Captcha
Site key and Secret key : Register your website and obtain the site key and secret key from here.
Theme : You can set background theme light or dark for the identification image that appears on the front end.
Languages : Select the language in which you want to display the characters in the image.
Enable Spam Verification from : Select the form that requires protection.
Besides this , re-CAPTCHA and PlayThru plugins are compatible with the Directory WordPress theme.
There are machines that run codes that run spammy codes to pretend like human beings and perform registrations on the website. With the captcha enabled the website will identify that the registration performed is by computers and not by the humans. By enabling this facility you can protect your websites from such attacks.