Curtains are o en hung on the inside of a building's windows to block the passage of light.
For
instance, at night to aid sleeping, or to stop light from escaping outside the building (stopping people
outside from being able to see inside, o en for privacy reasons). In this applica on, they are also
known as draperies. Curtains hung over a doorway are known as por ères.[2] Curtains come in a
variety of shapes, materials, sizes, colors, and pa erns. They o en have their own sec ons
within department stores, while some shops are completely dedicated to selling curtains.