3rd-Party Features are the tenth group on the Settings Page.
This article provides more information about each setting in the 3rd-Party Features group.
Use Google reCAPTCHA for Registration:
When enabled, the registration process will include a reCAPTCHA challenge that the user must pass before registration is allowed. This helps prevent most automated registrations.
Before this setting can be turned on, you must first complete the Site Key and Secret Key values provided by Google. Continue reading for instructions.
reCAPTCHA Site Key:
This part of the reCAPTCHA configuration is provided by Google. You must first register your site with Google, and then copy and paste the correct code into this textbox.
A direct link to the current Google setup page is provided just below the title of this setting. Click on that to get started.
reCAPTCHA Secret Key
This part of the reCAPTCHA configuration is provided by Google. You must copy and paste the correct code into this textbox, similar to the previous setting.