Up lights are used to light plants trees, and structures. They are the most common form of landscape lighting. A good rule of thumb is the taller the object to be lit the higher wattage the bulb should be to light it. By using the right bulb strength you can balance a landscape lighting design. This is never more true than with up lights.
Down lights are usually used to light driveways statues benches and pathways. They are also used for under soffits to light any building. They are different then moonlights because there are no shadows cast by them. See more Down Lighting.