Artificial intelligence (AI) is defined as computer systems that attempt to model human intelligence. The document discusses the early history of AI from Alan Turing's 1950 paper asking if machines can think to John McCarthy coining the term "artificial intelligence" in 1956. Current applications of AI include digital assistants like Siri, advances in machine learning and deep learning, and uses in areas like self-driving cars, medical diagnosis, and space exploration. Challenges for AI include computing power, intuitive thinking, and judging ability. The future of AI is promising but also presents risks if not developed responsibly.