In zoology, scales are protective epidermal structures composed of keratinized material that cover the integument of many vertebrates. These structures are highly diverse in composition and arrangement, varying from thin, flexible plates to overlapping, bony sheaths. Functionally, scales serve multiple roles, including mechanical protection against abrasion and predation, acting as a primary barrier to dehydration, and contributing to camouflage. Their presence and specific morphology are key characteristics used in the classification and ecological study of various groups, notably fish, reptiles, and amphibians.