This book provides a comprehensive exploration of the transformative field of brain-computer interfaces (BCIs) and neurotechnology. As the fusion of neuroscience, engineering, and artificial intelligence advances, this textbook guides readers through foundational principles and recent innovations that are reshaping how we understand and enhance brain-body abilities. From non-invasive BCIs and their role in communication and motor restoration to invasive BCIs designed for individuals with locked-in syndrome and beyond, each chapter delves into cutting-edge applications, including neurofeedback therapy and treatments for neuropsychiatric conditions like ADHD and depression. Additionally, the textbook addresses the crucial ethical, legal, and societal implications, exploring concerns over mental privacy, informed consent, and the commercialization of brain data. Intended for students, researchers, and professionals in neuroscience, biomedical engineering, and related fields, this text serves as both a technical guide and an ethical roadmap to the profound future of neurotechnology. This book contains more than 110 questions and answers: Download the Springer Nature Flashcards App free of charge and use exclusive additional material to test your knowledge.