Point Light
A bulb is a good example of a point light. A point light source distributes light
through space from a single point. It distributes beams of light evenly in all
directions. The intensity of the light is usually defined to fall off with the square
of the distance from the light to the surface. You could, however, define the
intensity to have no fall off at all. A point light needs a position to be completely
defined, and is often referred to as positional light.