Artificial intelligence (AI) is the intelligence demonstrated by machines, in contrast to the natural intelligence displayed by humans and animals. It is defined as the ability of machines to understand, think, and learn. The document traces the history of AI from Alan Turing's 1950 Turing Test to evaluate machine intelligence to John McCarthy coining the term "artificial intelligence" in 1955. It also categorizes AI into artificial narrow intelligence focused on specific problems, artificial general intelligence aimed at general problem-solving like humans, and artificial super intelligence exceeding human level abilities.