A transom window is a window above a door or over another window. It is often decorative and allows extra light into a space. Historically, a purely decorative transom window allowed building owners to demonstrate their wealth.
Transom windows come in many shapes, but many traditional transom windows are fan-shaped. They appear over entry doors and over doors that separate rooms within a building. Before the advent of air conditioning, transom windows opened to allow warm or cool air to circulate throughout office buildings while affording the workers some privacy. Transom windows can also be fitted with different types of glass.