bed sheet that wraps around mattress

On the other hand, the duvet cover is the decorative and protective layer that slips over the insert. It serves both aesthetic and functional purposes. A duvet cover can be thought of as the clothing for your bed—easily changeable to suit the season, refresh a room's decor, or simply for cleaning. They come in an array of fabrics, from crisp cotton percales to luxurious silks and cozy flannelettes, each adding a different texture and feel to your sleeping experience.

...

A duvet cover set typically includes a duvet cover and matching pillowcases, designed to envelop a comforter or duvet insert. It serves as a protective layer, shielding your expensive inner duvet from dirt, dust, and everyday wear, while also adding a touch of aesthetics to your bedroom decor. The cover is usually made from high-quality materials such as cotton, linen, silk, or microfiber, each offering a unique feel and benefit. For instance, cotton provides breathability, linen adds a rustic charm, silk ensures luxurious softness, and microfiber offers durability and easy maintenance.

...