A duvet cover is not only the cover for a duvet. It can also be use on blankets, quilts, comforters or any other bed cover.
The main advantage of a luxury duvet cover is its fabric, colour & design is same that of fitted bed sheet, flat/top bed sheet & pillow covers which gives a special 100% Egyptian cotton look & feel to your bedding in winters also.
On the other hand, covers of blankets & other bed covers don’t go with your fitted bed sheet, flat/top sheet & luxury pillow cases. It gives polyester, sateen look & feel to your bedroom which make sense in harsh winters & in the day time for decoration purpose of bedding combined with pillow shams.