This document provides an introduction to artificial intelligence. It begins with definitions of AI as a branch of computer science that aims to imitate human intelligence. It discusses the key components of intelligence like perception, reasoning, and learning. The document then gives a brief history of AI, highlighting important early developments, periods of enthusiasm and challenges. It outlines several applications of AI across different fields. It also classifies different types of AI based on approaches like symbolic, computational intelligence, and discusses concepts like narrow vs general AI. The document concludes with an overview of intelligent agents, their environment, and rational decision making.