A down comforter is a type of bedding filled with the soft, fluffy undercoating of ducks or geese. This natural insulation provides warmth while remaining lightweight, making it a popular choice for many people. Down comforters are often covered with a cotton or polyester shell, which helps to keep the filling in place and adds to the overall comfort. These comforters come in various weights and styles, allowing users to choose one that suits their climate and personal preferences. They are typically machine washable, but care should be taken to follow specific cleaning instructions to maintain their quality and longevity.