Answer:
The Earth is very old, and the study of Earth's past requires us to think about times that were millions or even billions of years ago. Scientists use the geologic time scale to illustrate the order in which events on Earth have happened.
The geologic time scale is an important tool used to portray the history of the Earth—a standard timeline used to describe the age of rocks and fossils, and the events that formed them. It spans Earth's entire history and is separated into four principle divisions.
