Earth

Earth is the planet that housed humans before operation cleanup.

Earth is the place that the Earthlings polluted making the Earthlings leave to the axiom ships, leaving WALL-Es to clean up the mess. After a while, all WALL-Es are destroyed except for one.

Before 2105
As Buy N Large continued to grow and dominate all industries, they start running out of space to dispose of rubbish.

2105
The human population reaches 200 Billion, and there are no places to dispose of rubbish. Buy N Large begins Mission Recolonise, sending starliners out into space (most notable being the Axiom), and leaving WALL-E Units, and incinerator units on the Earth performing operation cleanup.