Geological periods are divisions of Earth's history that help scientists understand the timing and sequence of events in the planet's development. These periods are part of a larger framework called the geological time scale, which organizes time into eons, eras, periods, epochs, and ages based on significant geological and biological changes. Each geological period is characterized by distinct rock formations, fossil records, and major events, such as mass extinctions or the emergence of new species. For example, the Mesozoic Era includes the Triassic, Jurassic, and Cretaceous periods, known for the dominance of dinosaurs and the development of flowering plants.