Silhouettes and shadows are two visual concepts which are often mistaken. A Silhouette is an outline of a person, animal, or object which is usually filled with a single colour. A shadow is the area where light from a source is blocked by an object.
A Silhouette can be created in a few different ways.
One way to create a Silhouette is to use natural light from the sun or moon or other light sources and block out the light except for the outline of the object or person. Silhouettes can also be created using photography, either digitally or on film, by underexposing the background and allowing only a black outline of the subject against a white background to appear in the photograph.
Shadows are usually darker than Silhouettes as they are made up of dark areas where no light has been allowed in. The size and shape of shadows vary depending on the angle of the sun and how close it is to an object. Shadows can also have different colours depending on what type of light source they are reflecting off, such as blue from fluorescent lights, yellow from incandescent lights, or red from firelight.
Conclusion
The difference between Silhouettes and shadows lies in their origin; Silhouettes are created by blocking out all light except for an outline while shadows occur when light is blocked by an object. Furthermore, shadows tend to be darker than Silhouettes and their size and shape vary depending on the angle of the sun.