What is the difference between feathers and scales?

Feathers and scales are both protective coverings found on animals, but they serve different purposes and are composed of different materials. Feathers, unique to birds, are made of keratin and provide insulation, waterproofing, and the ability to fly. Scales, found on reptiles, fish, and some mammals, are also made of keratin but serve primarily to protect the skin and reduce water loss. Additionally, scales are typically flat and overlapping, while feathers have a more complex structure with a central shaft and barbs.