Size:King What is a duvet cover?This is not comforter!!! Analogy: duvet is to duvet cover as pillow is to pillowcase. A duvet cover is a protective layer that slips over the duvet and has a closure. Because duvets and comforters can be expensive and difficult to clean, duvet covers are useful because they protect your comforter during use and are easily removed and easy to wash. With duvet covers, you can also quickly and easily change the look of your bed and room without having to completely redecorate. The duvet should fit snugly inside a duvet cover which can be removed and washed when needed. The duvet cover also allows you to change your style or color choice of your bedding with the simple switch of the cover. This allows for easy changes from season to season.