The goal of this book is to briefly introduce the techniques used in the design of Expert Systems. In the first chapter, we begin by presenting the basic concepts of artificial intelligence. The various schools of thought, the origins, and the domains of artificial intelligence are also discussed. In the second chapter, we will cover propositional logic, predicate logic, and various proof methods (equivalences and refutation). Chapter three is dedicated to representing the operational principles of expert systems, including the fact base, the rule base, and the inference engine. In chapter four, the logical programming language Prolog is briefly introduced, followed by chapter five, which includes examples of its use in demonstrating propositional logic or first-order logic, as well as in developing Expert Systems. In Chapter 6, we describe the IT elements required to develop an Expert System with a Web interface.To apply the various aspects covered in the different chapters, a series of exercises is provided at the end to conclude this book.