Window
an aperture in the wall of a building for the admission of light and air. Modern domestic windows are .
Modern domestic windows are usually rectangular openings occupied by movable frames filled with glass. The glazed portion or sash is hung or hinged in a frame, the horizontal stone forming the top of the window is the lintel, that at the bottom the sill, the sides of the opening are the jambs, and the portion between the outer face of the wall and the frame is the reveal. Architraves and other moldings commonly appear on the exterior. Venetian windows are large openings divided by piers or columns into three lights, sometimes arched. Windows projecting in a polygonal or semicircular form from the wall are termed bay or oriel windows; they were first introduced in Perpendicular style.