Different light types - ambient
Ambient is the most common form of light that we encounter in our daily lives. It is the overall light emanating from the sun or the artificial lights that illuminate a room. Often the direction of ambient light is vague, shadows are feint or limited and the coverage of light is fairly widely distributed. Ambient light also consists of the light reflected from other objects in the environment. As a source for general photographic lighting it merely provides illumination, but for more specific lighting scenarios props or additional lighting is required.
In the image of the pool ball, ambient light can be seen in the form of light from the sky as well as reflections from the concrete and the grass.