Cosmic time is a way of measuring time that relates to the entire history of the universe, starting from the Big Bang. It is often expressed in billions of years and helps scientists understand the age and evolution of the cosmos. This concept allows researchers to place events in the universe, such as the formation of galaxies and stars, in a broader context. In cosmic time, the universe is approximately 13.8 billion years old. This measurement is crucial for studying the life cycles of celestial objects, including stars, galaxies, and black holes. By using cosmic time, astronomers can better comprehend the processes that have shaped the universe over eons.