Does anyone know if the "All Mail" box in Gmail is a reference or a duplicate?

So, after alot of confusion, i've finally gotten IMAP Gmail set up in mail.app and on my iPhone. In mail.app, i've got the primary Inbox, Sent, Drafts, and Junk, corresponding to the default boxes on the gmail.com server.

On the iPhone, it works the same way, except that it didn't quite work with the Junk box, and on the iPhone, the junk box is still called "Spam" and is found under the "Gmail IMAP Account" sub-box. No big deal.

Now, the only last little bit of confusion is the "All Mail" box. Is it an archive? A duplicated backup? A reference? Does it operate like an iTunes playlist, where it isn't actually a new copy of each email?

Currently, I deleted everything out of the All Mail box in mail.app, but the All Mail box on gmail.com remained full. And next to each message, it shows the mailbox in which the message is in. So, it appears to be that it is simply a reference, a place in which I can view all my messages, from all the boxes. But it puts a copy of anything I do in there. Is it a copy, or a reference?

Thanks

 

Hey, I just got my answer. I attempted to delete an email from the All Mail box on gmail.com, and got this message:

"Moving conversations from All Mail to the Trash will remove them from all views, including labels and search results. This is because in Gmail, a conversation can be displayed in a variety of views, but there is only one copy. Are you sure you want to move the only copy to the Trash?"

I hope this answers the questions of some other people who have been wondering about this as well. I wonder why mail.app let me delete everything out of the All Mail folder without deleting it off the server. When a few new messages came into the All Mail box in mail.app just now, deleting them removed them from the server as well. So I guess I won't be doing that any more. Does anyone know of a way to force mail.app to download all the mail that is in All Mail on the server?