The bed skirt, to put it popularly, is a curtain hanging down from the bedside. Generally rectangular, mostly made of cloth, installed around the bed and placed under the mattress to prevent contamination of the mattress.

A bedding. Rectangular, mostly made of cloth, installed around the bed and placed under the mattress to prevent contamination of the bed curtain. Generally speaking, the drapery hanging from the bedside doesn't have to have a pleated edge. It depends on the style.