Earth is the realm of mortals, created by the Exarchs billions of years ago. It’s terrain and geography match the Exarch realm of Shamayim exactly. Shamayim and Earth exist as dual realms, or dimensions. Crossing between the two is possible but only with the expenditure of huge amounts of magic and even then it is a lengthy undertaking.
On Earth exists four primary races, Elves, Human, Dwarves, and Dragonborn.