A window valance is a form of window treatment that covers the uppermost part of the window and can be hung alone or paired with window blinds, or curtains. Valances are a popular decorative choice in concealing drapery hardware. Window valances were popular in Victorian interior design. A curtain is a piece of cloth intended to block or obscure light, or drafts, or water. A curtain is also the movable screen or drape in a theater that separates the stage from the auditorium or that serves as a backdrop.