Introduction
They obey our instructions with unlimited patience. They store the world’s knowledge and make it accessible in a split second. They are the backbone of modern society. Yet they are largely ignored. Computers. They comprise our crowning achievements to date, the pinnacle of all tools. Computer processors and software represent the most complex designs humans have ever created. The science of computers has enabled one of the most extraordinary transformations of our societies in human history. . . . You switch on your computer and launch the Internet browser. A one-word search for ‘pizza’ finds a list of pizza restaurants in your area. One click with the mouse and you are typing in your address to see if this restaurant delivers. They do! And they also allow you to order online. You choose the type of pizza you feel like, adding your favourite toppings. The restaurant even allows you to pay online, so you type in your credit card number, your address, and the time you’d like the delivery. You choose ‘as soon as possible’ and click ‘pay’. Just thirty-five minutes later there is a knock on your door. The pizza is here, smelling delicious. You tip the delivery guy and take the pizza to your table to eat. Ordering pizza is nothing unusual for many of us around the world. Although it may seem surprising, this increasingly common scenario with cheap prices, fast delivery, and access to such variety of food for millions of customers is only possible because of computers. In the situation above you might have spotted just one computer. If we take a look behind the scenes, the number of computers involved in bringing your pizza is astonishing. When you switched on your computer, you actually powered up many computers that all work together to make the display, mouse, keyboard, broadband, and main computer operate. Your computer linked itself to the Internet—which is a worldwide network of computers— with the help of computers of the phone company and Internet service provider. When you searched for ‘pizza’ the request was routed between several computers before reaching the search engine computers.