Ever wonder how the Internet really works? Most of us at one time or another have wondered what happens behind the scenes when surfing Web pages, sending email, or downloading files. You know instinctively that there must be many devices linking you to the other computer, but how exactly is the connection made? What makes up a message, and how does it find its way through the seemingly chaotic Internet back to your desktop? After all, it wasn't that long ago that incompatibility between various makes and models of computers made exchanging data a headache. Now everybody can connect to the Internet to share data and services without a second thought. How did the computer industry pull it off?
Most laypersons think the answer is technology, and to a point they're right. But the whole answer is that the Internet was brought together by a combination of technology and standards-specifically, de jure and de facto technical standards. De jure standards are set by trade associations; de facto standards are set by brute economic force. All the routers and switches in the world couldn't form the Internet without standards to make hardware, software, and telecommunications equipment compatible.
The products fueling the Internet were introduced in Chapter 1. Now we'll cover the underlying architectures that made all that technology possible. An understanding of the technologies and standards underpinning an internetwork will give you a clear picture of what happens in the background when you click a link in your browser.