Earth is the home planet of humanity and the place where human life has originated.
Earth
Role in the EnderVerse
Years before the events of Ender's Game, the Formics first entered the Sol System to conquer colonize the solar system for colonization. The humans, though technologically inferior, managed to fend off the Buggers. Some time later another invasion was attempted but with no avail. According to the Hive Queen, when the Formics realized individual humans were sentient, they chose not to invade a third time.
Ender's Game
In the book, Ender's Game, the Earth and Battle School in it's orbit plays a dominant role as the setting of the entire book except for the last chapter. The Earth was governed by a Hegemon, Polemarch and Strategos. The Hegemon was supposedly the ruler of the Earth, while in reality, he was a figurehead who effectively existed as a de jure compromise between the Polemarch and the Strategos. Due to overpopulation, the International Fleet set rigid taxes and restrictions on families with more than two children.