The Eocene Epoch is a geological period that occurred between 56 and 33.9 million years ago, following the Paleocene Epoch and preceding the Oligocene Epoch. Some synonyms for the Eocene Epoch include the Eocene Age, Eocene Period, and the Eocene System. The period was marked by a significant expansion of the world's flora and fauna, including the emergence of many modern mammalian orders. During the Eocene Epoch, the Earth's climate was relatively warm and stable, allowing for a flourishing of new species and the spread of tropical forests. Understanding the Eocene Epoch is crucial to comprehending the evolution of life on Earth and the planet's geological history.