A lamp shade is a decorative shade which typically surrounds a light source. Table lamps and floor lamps often use a lamp shade. The shade itself serves multiple functions, directing light upwards for ambient light, and downwards for nearby tasks. The funnel shape also helps heat to escape from the light bulbs. Some light may diffuse through the sides of the shade as well. The shade also protects your eyes from light-bulb glare and can become a part of your room's decorative style. Replacement lamp shades are a great way to refresh a lamp or light fixture. They attach to the lamp usually with a harp or fitter and finial.
An empire lamp-shade is a traditional lampshade shape where the bottom is wider than the top. It also features straight sides, forming a kind of triangular shape. The bottom of the shade spreads out more to distribute light, and to shine outward and downward for nearby tasks. The smaller opening at the top helps to funnel bulb heat away from the lamp. An empire lampshade coordinates well with a lamp base featuring straighter or simpler lines, but also works well with almost any lamp shape.
Sits on top of a harp or fitter, which is typically attached to a floor or table lamp. Spider-fitter shades sit on top of a harp fitter (a separate item). Uno fitter shades sit below the bulb with the uno fitter above. Clip-on shades clip directly onto the light bulb.