This is the first of three volumes in the series All Dimensions of Pathology , providing a comprehensive foundation for understanding disease mechanisms and the biological basis of pathology. The accompanying volumes focus on clinical applications and modern diagnostic techniques, and together the series offers an integrated overview of contemporary pathology. Fundamentals of Pathology introduces the essential principles underlying disease development, beginning with cellular biology, metabolism, genetic and chromosomal abnormalities, embryogenesis, and congenital disorders. Core concepts such as cell injury, cell death, inflammation, immune responses, hemodynamic disturbances, and mechanisms of carcinogenesis are presented in a structured and accessible manner. The volume further provides concise system-based introductory chapters that establish the morphological and functional framework of major organ systems, bridging basic mechanisms with organ pathology. Designed for medical students, pathology residents, and clinicians seeking a solid conceptual background, this book emphasizes clarity, scientific accuracy, and clinical relevance. By integrating molecular mechanisms with classical morphology, Fundamentals of Pathology serves as an essential starting point for mastering pathology as both a scientific discipline and a diagnostic practice.