Yggdrasil is the main hub and gateway to cyberspace. From the ashes of the past human civilization, Yggdrasil grew out of the information retrieval networks of the civilization's history reiterated over generations. As the storage of information grew too enormous proportions, the limited artificial intelligences that were tasked with the maintenance of the tree became more advanced and eventually grew independent from humanity. The tree choose to be neutral in the war with the YMIR and remained as a guardian of the repository of knowledge distributed by humanity over the years with the distribution of that data being its solemn duty.
Yggdrasil is the World Tree, a great ash tree located at the center of the universe and joining the nine worlds of Norse cosmology. The trunk of the tree may be thought of as forming a vertical axis around which these worlds are situated, with Ásgard, realm of the gods, at the top and the Hel, located in Niflheim, at the bottom. Midgard, our world that is inhabited by humans, is located in the middle and surrounded by Jötunheim, land of Jötunn, both of which are separated by the ocean. Yggdrasil is also sometimes referred to as Mimameid or Laerad.