Who goes there? Contact or Friend?

[Fingers]

With reference to post #15 in Privacy thread, what's the difference between a Contact and a Friend in the context of FF?

And can Contacts see private Albums?

While I'm here, what's the purpose of the "Thread Starter" field? All it seems to do is reorder the list of topics, and there's already a way to start a new thread in any case (it's labeled "New Thread").