Down feathers are soft, fluffy feathers found beneath the tougher outer feathers of birds, particularly waterfowl like ducks and geese. They provide excellent insulation, helping to keep birds warm in cold environments. Down feathers are lightweight and trap air, creating a layer of warmth without adding much weight. Due to their insulating properties, down feathers are commonly used in products like comforters, jackets, and sleeping bags. They are highly valued for their ability to retain heat while remaining breathable. However, ethical sourcing is important, as some down is collected from live birds, leading to concerns about animal welfare.