Totality refers to the complete coverage of one celestial body by another during an astronomical event, such as a solar eclipse. During totality, the Moon completely obscures the Sun, allowing observers in the path of totality to experience a brief period of darkness during the day. This phenomenon can last from a few seconds to several minutes, depending on the specific alignment of the Earth, Moon, and Sun. In addition to solar eclipses, totality can also occur during lunar eclipses when the Earth completely blocks sunlight from reaching the Moon. This results in the Moon appearing a reddish color, often referred to as a "blood moon." Totality in both cases provides unique opportunities for scientific observation and public engagement with astronomy.