What is a Duvet ?

Duvet (pronounced dōō-vā') is a French word meaning a down and feather filled bag used as a bed covering. The original duvets came out of rural Europe and were not closed; feathers could be added or removed to adjust warmth depending on the season.
 
Eider down is well known for its superior insulating value and was the original filling material used. Today “eiderdown” is sometimes used synonymously for duvet.
 
Duvets are also referred to as down comforters, down quilts, or down blankets.

Duvet Terminology Clarified

Duvets originally were an open bag, filled with feathers. That’s kind of messy for the modern home. Today a top and bottom cover, stitched (quilted) together, keeps the down evenly spread out. This is commonly referred to as a down quilt, down comforter, or just “duvet.”
 
But “duvet” can also refer to a separate cover, used to keep a down quilt / comforter clean. This extra cover is also called a duvet cover or down comforter cover.
 
Different parts of the world use different terminology. In Asia a duvet is commonly called a down quilt. In the US, a duvet can mean either a down comforter or a down comforter cover.
 
But you can know what’s what. If the item has down or feather filling, then it is a quilted comforter. But if it is only a cotton cover, then it is meant to be used over a quilted down comforter to help keep it clean.

Why a Down Comforter Cover is Important

You should wash your down comforter as little as possible. Washing takes natural oils out of down. If you wash your down comforter too much it will go flat and not keep you very warm.
 
A down comforter cover will help keep your down comforter clean and prevent the need for frequent washing.