From Halopedia, the Halo wiki
The planet featured jungles with exotic flora and fauna.
Humanity's discovery and control
While this planet bordered on UEG trade routes, it remained undetected for centuries. Sometime during the Human-Covenant War, the UNSC Diadochi crash landed on this planet. The survivors lived amongst the ruins of the ship for years until rescue teams finally discovered them, in a thriving community.
The planet was eventually named "Partition" in a nod to Earth's Diadochi conflicts. At some point a War Games simulation of the Diadochi crash site, called Exile, was created. Eventually, the data archival site was found and began to be studied, hoping to shift human understanding in Forerunner technology.
Partition is the setting for the Halo 4 multiplayer map Exile. The now-cancelled Halo Online set the map Edge on the planet, with the map hosting a Forerunner databank amidst a verdant series of grasslands, canyons and waterfalls. Due to the game's cancellation, any story or lore from that game isn't considered canon.
List of appearances