What did people use before computers were invented? When were the first smartphones invented? When was the first message sent on the internet? Computers were only invented within the past 100 years. Yet today, computers and other devices are everywhere in our lives - in classrooms, homes and public places. This fascinating book charts the history of computers, from the invention of the first calculating machines made of cogs and wheels during the 1640s to modern-day cloud computing and virtual reality headsets.