Final answer:
Direct light casts hard-shadows with sharp outlined edges, while diffused light produces softer shadows. Backlight often results in a silhouette rather than a sharp shadow.
Step-by-step explanation:
The type of light that casts hard-shadows with sharp outlined edges is known as direct light. Direct light comes from a single, coherent source such as the sun on a clear day or a spotlight in a dark room, producing shadows with well-defined, crisp edges. This is unlike diffused light, which occurs when light reflects off a rough surface, scattering in many directions, and creates softer shadows with less distinct edges. For instance, an overcast sky or light passing through a frosted glass diffuses the light, reducing the hardness of the shadows. Directional-diffused light and backlight do not produce hard-shadows with sharp edges. Backlight, a term for light coming from behind the subject, generally creates a silhouette rather than a sharply defined shadow on the ground or surrounding objects.