An opening in the wall or roof of a building or vehicle, fitted with glass in a frame to admit light or air and allow people to see out Window walls have a break between the glass, with slab covers used to conceal the concrete.
What is the purpose of window curtain? Curtain | interior decoration | Britannica curtain, in interior design, decorative fabric commonly hung to regulate the admission of light at windows and to prevent drafts from door or window opening.