The chapter introduces the concept of expert systems, which are computer programs designed to solve problems using knowledge from human experts, simulating human reasoning. The author, Arthur W. DeTore, highlights the limitations of human memory and the need for advanced technology to enhance decision-making in fields like medicine. Artificial intelligence (AI) is defined as the branch of computer science that focuses on symbolic processing, allowing for the development of nonlinear relationships among concepts. Expert systems, a type of AI, consist of a knowledge base, an inference engine, and a user interface. The knowledge base stores programmed knowledge, the inference engine applies this knowledge to solve problems, and the user interface facilitates interaction. The chapter also discusses the development of expert systems, including inductive and deductive approaches, and their applications in various industries, particularly in insurance for tasks such as marketing, underwriting, and claims adjudication. These systems are valuable for consistent decision-making, expanding knowledge resources, and training users. However, they do not replace experts but serve as productivity aids.The chapter introduces the concept of expert systems, which are computer programs designed to solve problems using knowledge from human experts, simulating human reasoning. The author, Arthur W. DeTore, highlights the limitations of human memory and the need for advanced technology to enhance decision-making in fields like medicine. Artificial intelligence (AI) is defined as the branch of computer science that focuses on symbolic processing, allowing for the development of nonlinear relationships among concepts. Expert systems, a type of AI, consist of a knowledge base, an inference engine, and a user interface. The knowledge base stores programmed knowledge, the inference engine applies this knowledge to solve problems, and the user interface facilitates interaction. The chapter also discusses the development of expert systems, including inductive and deductive approaches, and their applications in various industries, particularly in insurance for tasks such as marketing, underwriting, and claims adjudication. These systems are valuable for consistent decision-making, expanding knowledge resources, and training users. However, they do not replace experts but serve as productivity aids.