Geochronology is the scientific study of determining the age of rocks, sediments, and fossils. It uses various dating methods, such as radiometric dating, to measure the decay of radioactive isotopes in minerals. This helps scientists understand the timing of geological events and the history of the Earth. By establishing timelines, geochronology aids in reconstructing past environments and understanding the evolution of life. It plays a crucial role in fields like paleontology and archaeology, allowing researchers to date artifacts and fossils, thereby providing insights into the Earth's history and the development of human civilization.