Earth history refers to the timeline of events that have shaped our planet over billions of years. It includes the formation of the Earth around 4.5 billion years ago, the development of its atmosphere and oceans, and the emergence of life. Major geological periods, such as the Paleozoic, Mesozoic, and Cenozoic, mark significant changes in climate, landforms, and the types of organisms that existed. Throughout its history, Earth has experienced dramatic events, including mass extinctions and the movement of tectonic plates. These processes have led to the formation of mountains, oceans, and continents, influencing the evolution of life. Understanding Earth history helps scientists learn about past climates and predict future changes.