Explanation of 'Introducing Broker'?

I know this question should be directed to my dealer (which I will contact on Sunday night as soon as they open) BUT (thanks to a message thread started by someone else in the forum ‘Rate your broker’ or something like that) I found that a broker called Forexion is the ‘Introducing Broker’ for GCI Financial (where I have my account).

What I don’t understand is that Forexion offers a 500:1 leverage whereas GCI only offers a 200:1 leverage. 500:1 is better right? More ‘bang for your buck’ right?

My question is how can an ‘Introducing Broker’ be offering a higher leverage than the actual dealing desk itself?

Not to mention the other benefits apparantely offered by Forexion i.e. Rebate Programme and Affiliate Program.

I would like to know what the meaning of ‘Introducing Broker’ is I suppose and where an ‘Introducing Broker’ fits into the picture.