http://www.edri.org/files/2012EDRiPapers/how_the_internet_works.pdf

This booklet is intended to provide policy-makers with a basic overview of Internet and Internetrelated technologies.
The aim is to provide a user-friendly reference guide to some of the key technologies that are at the core of the Internet. We hope that this will provide a valuable reference tool, cutting through the jargon and demonstrating the functioning of the open Internet, on which so many civil rights and so much economic activity now rely.