Understanding tissues and cells at microscopic and molecular levels is essential for diagnosing disease and interpreting pathology. This book covers cell structure, membrane dynamics, intracellular trafficking, and the major tissue types with clear micrographs and explanatory diagrams. Staining methods, microscopy techniques, and histopathologic correlates are included to show how normal histology transitions to disease states. Attention to cellular signaling, the cytoskeleton, and cell cycle control links basic biology to oncology, regeneration, and repair. Clinical pearls highlight how histologic patterns inform diagnosis, prognosis, and therapeutic choices. A foundational resource for students, pathologists, and clinicians who rely on microscopic anatomy.