The term Neigong, often translated as "internal skill," is widely recognized but frequently misinterpreted, particularly with respect to its physiological and psychological dimensions. This misinterpretation arises in large part from the decline of correct methods for integrating body, breath, and mind in contemporary practice. Consequently, disciplines such as martial arts, Qigong, meditation, internal cultivation, and therapeutic applications are often approached as abstract ideals rather than as attainable, embodied practices. Effective engagement with Neigong requires a clear understanding of its foundational principles and the capacity to apply them systematically. The aim of this volume is to articulate those principles and to provide a structured framework grounded in anatomy and physiology. Such a framework enables practitioners to assess their progress with greater objectivity and to cultivate verifiable internal skills. While this study is informed by the Wing Chun tradition, its scope is not limited to it. The discussion situates Neigong within a broader intellectual and practical context, drawing on Taoist, Buddhist, and Confucian traditions, as well as the theoretical perspectives of Chinese medicine. In doing so, it seeks to serve as a comprehensive resource for the study and practice of Wing Chun, Qigong, meditation, and related Chinese internal arts.