Zoology is the branch of biology dedicated to the study of animal life, encompassing the classification, structure, function, behavior, and evolution of animal species. The discipline examines the physiological processes that sustain life in various forms, ranging from microscopic invertebrates to complex vertebrates. Areas of study include comparative anatomy, ethology, which investigates animal behavior in natural contexts, and systematics, which determines evolutionary relationships among different groups of animals. The field contributes fundamental knowledge to understanding biological complexity and ecological interactions within global ecosystems.