The locations and size of apertures matter a great deal if you want to utilize natural light in your building. Evenly-distributed light is critical to good daylighting, so apertures that are evenly distributed are useful.
The physical properties of the materials, coatings, and constructions that make up windows and skylights. Good glazing properties are important because they control the amount of daylight, quality of light, and amount of solar heat gain let into the building.
Aperture placement and area are important because strategic use of windows and skylights can help you achieve thermal and visual comfort passively, saving both energy and money.