What are App Domains in Facebook Apps?

Question

I want to add the ability to \'login with Facebook\' to my site. But I am confused when I register my site in Facebook Apps. What should I input into App Domains

Answer 1

To add to the answers above, the App Domain is required for security reasons. For example, your app has been sending the browser to "www.example.com/PAGE_NAME_HERE", but suddenly a third party application (or something else) sends the user to "www.supposedlymaliciouswebsite.com/PAGE_HERE", then a 191 error is thrown saying that this wasn't part of the app domains you listed in your Facebook application settings.