Human: What is the difference between a duvet and a comforter? Assistant: 
The primary difference between a duvet and a comforter is that a duvet is meant to be filled with a down-based filling and a comforter is usually filled with a synthetic material such as polyester. A duvet is usually also thinner and lighter, making it easier to store and transport. A comforter is generally thicker and heavier, providing more insulation and warmth.