A 'thread' is a collection of posts.
A 'forum' is a collection of threads.
'Suggestions' is a forum.
'Miscellaneous' is a forum.
'Christian Chat Forums' is not a 'forum' - it is a collection of forums on a web site.
'Christian Chat' is a web site and not a forum.
There is no proper way to refer to the whole thing (the web site - a collection of forums) using the word 'forum' (singular). However, the word 'forums' (plural) may be used - i.e., "the forums" - as in 'informal' reference.
So - the next time someone says 'forum' (singular), you may appropriately assume that they mean 'forum' and not 'forums' - because, the two are distinctly different. And, if they confuse or conflate the two - then, it is their error and not yours.