A duvet is a type of blanket that is filled with soft materials, such as down feathers or synthetic fibers, providing warmth and comfort. It is typically used as a top covering on a bed and is often placed inside a removable cover called a duvet cover, which can be washed easily. Duvets come in various sizes to fit different bed dimensions, such as twin, full, queen, and king. They are popular in many countries for their simplicity and versatility, allowing users to change the duvet cover for different styles or seasons without needing to replace the entire blanket.