It's an overloaded term that different people use for different things. At World Labs we think about three major categories of world models:

- Renderers output pixels or views of a world, either the real world or a generated world

- Simulators predict how the world responds to actions

- Planners predict actions for an agent to make to affect some change in the world

Under this taxonomy, Atlas is somewhere between renderer and simulator. It predicts high-quality views of a consistent 3D world (renderer) but it can also predict explicit 3D to aid in simulation. Atlas doesn't currently predict actions to directly drive a robot, so it isn't natively a planner; but its simulation abilities can help train another model to be planner.

Source: https://www.worldlabs.ai/blog/taxonomy-of-world-models