This concise and sober book presents a brief history of AI, explaining in clear language the central engineering innovations that have produced the current revolution. It distinguishes between imagined dangers and the very real problems that AI is creating. Spread across seven short and accessible chapters, this book explains the developments behind deep learning and the applications of deep neural networks (DNNs). It addresses both the imagined and actual risks posed by the AI revolution, before outlining the elements of a rational public policy on AI, covering topics like tech monopolies, disinformation, bias, hate speech, intellectual property rights, and inequality.