A location is part of a world, meaning several locations can share one world (think “domain”), but more than one location can be active at the same time. What all location within a world should have in common is that they run on the same app. This app can be the Portal Hopper or some other graphics engine.
When wandering between Locations, the Portal Hopper will retain its information such as a game score or your name. But when hopping to another world, all this information is flushed to prevent the Hopper from hogging memory.