I'll give you a few different answers then.
Well, my opinion is going to be simple then. Globex is a bridge between the cash treasury market, and stocks both in dark pools and on listed exchanges. It's also an exchange for commodities, but I don't really mess with that.
It is connected to the NYSE and NASDAQ data centers with an ultra low latency connection (much faster than fiber optic). It is an arena both in terms of technology and intellectual property/trade secrets. You trade against the best traders on earth.