Introduction to
Digital Computation

Everything is a computer. Okay, not literally everything, but far more than you might suspect. You're probably aware that desktops, laptops, and the phones in our pockets are all general-purpose computers with essentially the same hardware, running essentially the same operating systems and software. You may be less aware that the same is true of many other devices in our personal and professional lives. Smart refrigerators, the X-ray system at your dentist's office, modern gaming consoles, business phone systems, fast food ordering kiosks, video surveillance systems — computers, all of them. The cloud, which backs up your iPhone photos and powers your apps? That's just someone else's computer. Those AI datacenters that are always in the news? Those are just high-tech warehouses with super-expensive air conditioners, full of computers.

The digital computer is ubiquitous and becoming ever more so. And while the world of technology changes rapidly, the foundational architecture of the digital computer has remained largely unchanged for decades. If this book were written in 1986, its core concepts would be essentially the same, and I suspect the same will be true in 2066.

This book is for anyone who wants to understand those core, unchanging concepts on which our modern technological world is built. I'll teach you how digital computers actually work; not just how to use them, but what's happening underneath. No prior knowledge or experience in computation is required. All you need is curiosity and a willingness to think logically and explore how the pieces fit together.

This is an interactive, first-principles guide to the fundamentals of modern digital computing. You'll engage with concepts through real-world examples, hands-on activities, and visual diagrams that break down complex systems into understandable parts. We'll build your understanding one layer at a time: from the basic building blocks of binary, through processors, operating systems, and networks, all the way up to cloud infrastructure and information security. Every concept connects to the one before it.

If you're aiming for a career in cybersecurity, systems administration, or any of the other technical fields of today and tomorrow, this knowledge is essential.

So, as Lewis Carroll's King of Hearts would say: let's begin at the beginning — in our case, defining the very concept of digital computation itself.