According to science, shadow is an image of an object created on a flat surface due to obstruction of light. In the eyes of art loving people, shadow is not just a 2D impression or image of an object on a flat surface but much more than this. Shadows add emotions, feelings and depth to a scene. Marvelously captured shadows enhance the beauty of the photograph. Ruth E. Renkel expressed shadows beautifully:
Never fear shadows.
They simply mean there’s a light shining somewhere nearby.