An accessible guide to our digital infrastructure, explaining the basics of operating systems, networks, security, and other topics for the general reader.

Includes index.

Introduction -- Part I. Single process. Steps -- Processes -- Names -- Recursion -- Limits : imperfect programs -- Limits : perfect programs -- Part II. Interacting processes. Coordination -- State, change, and equality -- Controlled access -- Interrupts -- Virtualization -- Separation -- Packets -- Browsing -- Part III. Unstoppable processes. Failure -- Software failure -- Reliable networks -- Inside the cloud -- Browsing revisited -- Part IV. Defending processes. Attackers -- Thompson's hack -- Secrets -- Secure channel, key distribution, and certificates -- Bitcoin goals -- Bitcoin mechanisms -- Looking back -- Index of metaphors and examples -- Subject index.