Down-filled jackets are outerwear designed for warmth, using insulation made from the soft feathers found under the feathers of ducks or geese. This natural material is lightweight and provides excellent insulation, trapping heat close to the body while allowing for breathability. These jackets are popular for cold weather activities, such as skiing or hiking, due to their ability to keep wearers warm without adding excessive bulk. Many down-filled jackets also feature water-resistant or waterproof outer layers, making them suitable for various weather conditions.