The Structure of Digital Computing is a book that was mostly written over a decade ago, but still provides a gentle introduction to current technologies, including big data and devices / Internet of Things. Chapter 5 is an introduction to data science and big data. Chapter 1 gives an overview of digital computing, ending with the current emergence of devices (now beginning to be called the Internet of Things). Chapter 2 is how the increasing power of computing components and their decreasing costs impacts not just computing, but also storage, networking, software and data. Chapters 3 and 4 take the view that genuine innovation is relatively rare in digital computing and why, even when it does happen, it can still take several years to influence products in the market.