This book is a comprehensive overview of the fundamentals and applications of extended reality (XR) with practical insights and real-world examples. Introduction to Extended Reality (XR) Technologies is a thorough guide to understanding the fundamentals, concepts, and key aspects of XR technology, including augmented reality (AR), virtual reality (VR), and mixed reality (MR). The book explores how extended reality blends the physical and virtual worlds, transforming industries such as education, healthcare, and entertainment. Each chapter covers key aspects, from foundational principles to practical applications, with real-world examples illustrating the technologies' potential. By addressing current trends, challenges, and future directions, the book serves as an essential resource to explore the evolving world of these technologies. This book comprises 12 chapters, each presenting an in-depth overview of extended reality (XR) technologies. The first section details an introduction to extended reality technologies, covering augmented reality (AR), virtual reality (VR), and mixed reality (MR), and how they're rapidly growing across various industries. The second section examines the potential of these technologies and how they'll revolutionize different sectors, like aviation and tourism. The section also includes discussions on specific applications of XR technologies and the development advantages for each sector. The third section discusses how augmented reality and virtual reality play a pivotal role in healthcare sectors, allowing for disease diagnosis and treatment planning. Audience This book is intended for engineers, IT industry professionals, healthcare industry professionals, computer engineering and the electronics sector.