Yes. It keeps a replica of the data in a remote location. One of those replicas is active and the other is passive and hidden, and when I want to change from one site to another, move the server and have everyone believe that it moved from one location to another, all I'm doing is exposing the hidden replica and hiding the original one. In this fashion, I don't actually have to transmit all the data across the network. You could think of it as a very sophisticated shell game.
On November 3rd, 2011. See this statement in context.