Digital networks are so deeply embedded in our everyday actions and expectations that we are barely aware of their presence. Subtle and occasionally sinister, they manage, moderate and curate our global connections and relationships, in a manner that would have been unthinkable to all but a few wildly prescient science-fiction writers even a generation ago.

Networks sit at the very heart of every message, online purchase, travel choice and entertainment decision that we initiate. Despite their pervasive influence, few of us really understand the complex structure of rules, standards, processes and assumptions under which our new digital overlords operate. Christopher Brinton and Mung Chiang offer an open and accessible pathway through the complexity of network design and deployment, and offer a readily understood, yet commendably deep, analysis of the technology and its operation.

A key strength of this study is its depth, for while the topics themselves are often apparently straightforward (how your home wi-fi hub communicates, for example) the authors are admirably keen to drill down into the really important detail on which networks are founded, ensuring that we gain a real grasp of how the essential structures behave and operate. This no-punches-pulled approach extends beyond the physical technology into the logic of prediction and inference in network systems ¨C of critical importance to our understanding of how networks support and influence our decisions. Each of the book¡¯s six sections takes on a theme: accessing and sharing resources, ranking and ordering, the wisdom (and folly) of crowds, traffic routeing and management. While this will be largely familiar territory to computer scientists, the issues raised now have much wider relevance. Much of the material has already been used, we are told, in a massive open online course that has had more than 100,000 students in the past three years. The examples are of equal relevance to the everyday user of network services as to the specialist, and while every network author¡¯s favourite human examples ¡°Alice¡± and ¡°Bob¡± make several appearances, they have now strayed well beyond their previous territory ¨C to good effect.

Most of the sections conclude with a conversation with a significant subject expert and the authors haven¡¯t asked just anyone for a chat: Eric Schmidt of Google/Alphabet and Robert Kahn and Vint Cerf, the co-inventors of the TCP/IP protocol, are among those interviewed, which adds to the book¡¯s appeal. These are industry insiders in the true sense and their insights offer an extra layer of veracity to the material.

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In a world in which it is increasingly difficult to live without a profoundly intimate relationship with digital networks ¨C whether you like it or not ¨C the material presented in this text could usefully form a universal part of public education. Only with an understanding at this level of how the ¡°plumbing¡± of digital networks behaves can anyone give truly informed consent regarding how their personal data ¨C and by extension, their lives ¨C are managed by them. To describe this book as a course in digital citizenship would not be to overstate its importance.

John Gilbey teaches in the department of computer science, Aberystwyth University.

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The Power of Networks: Six Principles That Connect Our Lives
By Christopher G. Brinton and Mung Chiang
Princeton University Press, 328pp, ?24.95
ISBN 9780691170718 and 9781400884070 (e-book)
Published 4 January 2017