Scientists use the geological time scale to organize Earth's history. This framework categorizes the Earth's history into different time intervals, including eons, eras, periods, epochs, and ages based on significant events, such as mass extinctions and major geological changes.
Additionally, layers of rock (strata) are studied to understand the chronological sequence of events, while the fossil record provides evidence of past life forms and their evolution over time. Mass extinctions, which are significant events that led to widespread and rapid decreases in biodiversity, also play a key role in understanding the Earth's biological and geological history.
So, to summarize, the geological time scale is the primary tool scientists use, with the fossil record and rock layers providing essential data for organizing and interpreting Earth's history.