Virtual Reality (VR) is the use of computer technology to construct an environment that is simulated. VR places the user inside and in the center of the experience, unlike conventional user interfaces. Users are immersed and able to connect with 3D environments instead of seeing a screen in front of them. The computer has to role to provide the experiences of the user in this artificial environment by simulating as many senses as possible, such as sight, hearing, touch and smell. In Augmented Reality (AR) we have an enhanced version of the real physical world that is achieved through the use of digital visual elements, sound, or other sensory stimuli delivered via technology. It can be seen as VR imposed into real life. In both VR and AR the experience is composed of a virtual or extended world, an immersion technology, sensory feedback and interactivity. These elements use a multitude of technologies that must work together and presented to the user seamlessly integrated and synchronized. This book is dedicated to applications, new technologies and emerging trends in the fields of virtual reality and augmented reality in healthcare. It is intended to cover technical areas as well as areas of applied intervention. It is expected to cover hardware and software technologies while encompassing all components of the virtual experience. The main goal of this book is to show how to put Virtual Reality in action by linking academic and informatics researchers with professionals who use and need VR in their day-a-day work, with a special focus on healthcare professionals and related areas. The idea is to disseminate and exchange the knowledge, information and technology provided by the international communities in the area of VR, AR and XR throughout the 21st century. Another important goal is to synthesize all the trends, best practices, methodologies, languages and tools which are used to implement VR. In order to shape the future of VR, new paradigms and technologies should be discussed, not forgetting aspects related to regulation and certification of VR technologies, especially in the healthcare area. These last topics are crucial for the standardization of VR. This book will present important achievements and will show how to use VR technologies in a full range of settings able to provide decision support anywhere and anytime using this new approach.