Rose window is often used as a generic term applied to a circular window, but is especially used for those found in Gothic cathedrals and churches. The windows are divided into segments by stone mullions and tracery. The term rose window was not used before the 17th century and comes from the English flower name rose.
Exterior of the rose at Strasbourg Cathedral, France
Interior of the rose at Strasbourg Cathedral
Architectural drawing of the rose window of Strasbourg Cathedral
Oculus – Florence Cathedral
A window is an opening in a wall, door, roof, or vehicle that allows the exchange of light and may also allow the passage of sound and sometimes air. Modern windows are usually glazed or covered in some other transparent or translucent material, a sash set in a frame in the opening; the sash and frame are also referred to as a window. Many glazed windows may be opened, to allow ventilation, or closed, to exclude inclement weather. Windows may have a latch or similar mechanism to lock the window shut or to hold it open by various amounts.
Alabaster "mullion"-divided decorative windows in Santa Maria La Major church (Morella, Spain)
Alabaster window in the Valencia Cathedral. Note the asymmetrical, slanted left side of the wall-frame, which lets sun rays reach the chancel
Ancient Egyptian sandstone window grill from a palace of Ramesses III, now in the Metropolitan Museum of Art (New York City)
Fragment of a Roman window glass plate dated to 1st to 4th century CE. Note the obvious curvature; this is not a flat pane