JFBConnect install before Jom Social ...

Del,
JFBConnect itself doesn't store any additional profile information from Facebook. For Joomla, we only import the user's name and email address. We rely on 3rd party systems, like JomSocial, for storing additional profile data.

So, if you start with just JFBConnect, you'll allow your users to easily register on your site and log back in using their Facebook credentials. Once you install JomSocial, you can configure JFBConnect to automatically import the user's Facebook profile data into JomSocial whenever they login to the site.

I hope that explains, but if not, or you have any other questions, just let us know.

Thanks,
Alex