The term Penumbra refers to the partially shaded outer region of a shadow, particularly during an eclipse. It is the area where the light source is only partially blocked, creating a gradient of light and darkness. This phenomenon can be observed during solar and lunar eclipses, where the Moon casts a shadow on the Earth or vice versa. In addition to its astronomical significance, the concept of penumbra is also used in various fields such as photography and art, where it describes the transition between light and shadow. Understanding penumbra helps in creating depth and realism in visual representations.