Daylight and sunlight are two very different things. While direct sun in small amounts may add delight to interiors (especially on cold winter days), too much sun creates uncomfortable glare and heat gain in buildings. The art of daylighting is in designing openings that admit enough diffuse natural light from the sun and sky without allowing too much direct sun to penetrate, yet still preserve views. Electric lights are either dimmed or switched off by automatic controls and natural light is harvested to illuminate an interior space.