Double-hung windows are a popular type of window that features two movable sashes, allowing both the top and bottom sections to slide up and down. This design provides excellent ventilation options, as you can open either sash to let in fresh air while keeping the other closed. These windows are commonly found in residential homes and come in various styles and materials, including wood, vinyl, and aluminum. Double-hung windows are easy to clean since both sashes can tilt inward, making it simple to access the exterior glass from inside the home.