Histology examines how cells and extracellular matrices assemble into tissues that perform specific physiological roles. Volume 1 introduces microscopy techniques, staining methods, and the four basic tissue types with high-quality photomicrographs and schematic summaries. Each tissue is described in terms of cellular components, ultrastructure, and functional implications for organ performance. Correlative notes link microscopic features to clinical signs and common pathological changes. Learning aids such as labeled slide guides and comparison tables support lab identification skills and exam preparation.