Chronostratigraphy is a branch of geology that focuses on the age and time relationships of rock layers, or strata. It helps scientists understand the sequence of geological events and the history of the Earth. By studying the characteristics of different rock layers, researchers can determine when specific events occurred, such as volcanic eruptions or the formation of mountains. This field often uses techniques like radiometric dating to establish the age of rocks and fossils. Chronostratigraphy is essential for constructing the geological time scale, which divides Earth's history into different periods, such as the Paleozoic and Mesozoic eras, helping to organize our understanding of Earth's past.