Tell me what the shadow you have seen looks like

It is black, has a clear outline, and has the same shape as the object.

According to people's descriptions and observations, shadows are usually dark areas produced by objects blocking light, and their shapes are similar to the objects blocking light. Shadows are usually black or dark in color and absorb light without reflecting it. The outline of the shadow can be clearly visible, or it can change depending on the intensity of the light and the shape of the object.