Geological periods are distinct intervals of time in Earth's history, characterized by specific geological and biological events. These periods are part of a larger framework called the geological time scale, which divides Earth's 4.6 billion-year history into eons, eras, periods, epochs, and ages. Each period is marked by significant changes in the planet's climate, geography, and life forms. The most well-known geological periods include the Paleozoic, Mesozoic, and Cenozoic eras, each containing several periods. For example, the Jurassic period, part of the Mesozoic era, is famous for the dominance of dinosaurs. Understanding these periods helps scientists study Earth's evolution and the history of life.