This sketch is more important that you might think. Go back to 1964 and think about where computing was at the time. In a computer age roughly analogous to stone knives and bear skins, Paul Baran of the RAND Corporation envisioned a communications network that would survive a major enemy attack. The sketch shows three different network topologies described in his RAND memorandum, “On Distributed Communications: 1. Introduction to Distributed Communications Network” (August 1964). The distributed network structure offered the best survivability. This is why we have the Internet today. Thanks, Paul. We owe you a Coke.