Hopper windows are a type of window that opens inward from the top, allowing for ventilation while maintaining privacy. They are often used in basements or small spaces where traditional windows may not fit. The design helps to keep rain out while still allowing fresh air to circulate. These windows are typically hinged at the top and can be opened by pushing the bottom inward. Hopper windows are popular in both residential and commercial buildings due to their energy efficiency and ability to enhance natural light. They can be made from various materials, including vinyl, wood, and aluminum.