Artificial Intelligence(AI) is a big field, and this is a big book. We have tried to explorethe full breadth of the field, which encompasses logic, probability, and continuous mathemat-ics; perception, reasoning, learning, and action; fairness, trust, social good, and safety; andapplications that range from microelectronic devices to robotic planetary explorers to onlineservices with billions of users.The subtitle of this book is “A Modern Approach.” That means we have chosen to tellthe story from a current perspective. We synthesize what is now known into a commonframework, recasting early work using the ideas and terminology that are prevalent today.We apologize to those whose subfields are, as a result, less recognizable.