The collection of ideas, theories, ways of thinking, and ways of doing that have come together under the umbrella of information technology did not start together. Each strand has its own inception and development; sometimes different strands come together, or one strand splits apart, to follow different historical courses. As a result, I will be jumping about in time, following one strand up to the twentieth century, and putting it aside to go back to the source of another. Although I have taken the start of the computer age to be around 1945, many of the themes that I discuss remained outside the realm of the computer or the digital world for much longer. For example, mainstream photography, now absolutely part of the digital world, did not become so until after 1980. In such cases, I will follow each theme through my lifetime, to the point where it is absorbed into or enveloped by this new reality—or perhaps more accurately, until the new ways of thinking and doing expand to include it. Among the themes that will emerge in a roundabout way is a notion that is key to the modern world—that of data. This now all-pervasive idea, which is essentially both the raw material and the product of all computational processes, and encompasses pictures and sounds as well as text, numbers, and a lot of other things, began to emerge explicitly around the start of the twentieth century. It is now hard to think of many aspects of what I will be discussing without this notion in the background.