A Visual Positioning System (VPS) is a localization technique to compute one’s current position in the world. It is an enhancement to GPS (Global Positioning System).
VPS uses images of the environment. The current camera view is mapped to the existing images of a scene. This provides a more accurate position and orientation than with GPS. VPS only works, if the environment has been scanned before.
Google uses VPS in its navigation apps and provides the technique with the Geospatial API. Niantic Lightship provides its own Visual Position System. Developers can create private or public wayspots for placing AR content in the world.