The answer to 'skylight or skylight' is that skylights and roof windows are both types of overhead windows that let in natural light, but they have some key differences in terms of features, benefits, costs, and use cases. Skylights are typically fixed, dome-shaped windows installed directly into the roof, while roof windows are hinged, can be opened, and are often installed in a vertical wall section of the roof.
Skylights generally provide more ambient light and a larger viewing area, but they can be more expensive to install and may require more complex roofing work. Roof windows offer more ventilation and accessibility, but have a smaller glass area. The best option depends on your home's architecture, lighting needs, and budget.