This document provides an overview of artificial intelligence (AI). It defines AI as "the science and engineering of making intelligent machines, especially intelligent computer programs" according to John McCarthy, the father of AI. The document explains that AI is a way to make computers and robots think intelligently like humans. It also lists several fields that contribute to building intelligent systems, including computer science, biology, psychology, linguistics, mathematics, and engineering. The document discusses challenges with organizing vast amounts of changing real-world knowledge for AI systems. It provides examples of applications of AI in gaming, natural language processing, and expert systems. In closing, it notes both optimistic and pessimistic views about the future impacts of AI.