This book gives a basic introduction to navigation, from key concepts, basic principles, main technologies, equipment systems to the knowledge frame of navigation. The ten chapters fall into three parts: Chapters I~III introduce the elementary knowledge of navigation; Chapters IV~IX are devoted to the basic principles, and the optimization principle of integrated navigation as well; and Chapter X discusses the application of marine navigation, indicating the basic outline of the marine navigation system. The book clearly reflects the systematic idea of navigation knowledge from multiple perspectives, which is helpful for readers to build a holistic understanding of navigation from the concept, principle, characteristics, technology to the equipment system. At the end of each chapter, reflections beyond the fundamental knowledge of navigation are included to help readers further develop their scientific thinking and general literacy. This book is written primarily for students majoring in navigation, and it may also be of interest to researchers and practitioners engaged in navigation.