With all the recent talk of cloud computing, we think less and less about the physical infrastructure that makes the world as we know it work. Wireless connections support this idea that we don't really need to be tied down to anything. And yet, we're always using backbone somehow.
Internet Backbone is the physical connections between various networks--large corporate, military and educational ones-- that allow information to flow between them.
Logically, it makes sense. The interwebs have to touch, have to be connected. But it is a little mind-boggling to think that we're so locked in, so bound together, even as the networks themselves are like ever expanding stars in the universe. Atlas still holds us up.