Mirror world

A mirror world is a representation of the real world in digital form. It attempts to map real-world structures in a geographically accurate way. Mirror worlds offer a utilitarian software model of real human environments and their workings.
The term differs from virtual worlds in that these have no direct connections to real models and thus are described as fictions, while mirror worlds are connected to real models and lie nearer to non-fiction. It's closely related to Augmented Reality but a mirror world can be seen as an autonomous manifestation of digitized reality including virtual elements or other forms in which information is embedded.
The term in relation to digital media is coined by Yale University computer scientist David Gelernter. He first speaks of a hypothetical mirror world in 1991.
Open geo-coding standards allow users to contribute to mirror worlds. Thus it's possible to make one's own geographical data appear as a new "layer" on one's computer's copy of a mirror world.
Examples.
Programs such as Google Earth and Microsoft Virtual Earth are examples of 3D mirror worlds.
The video game "Anteworld" of the Outerra engine is a mirror world that mirrors the entire planet Earth at a 1:1 scale. While the game is currently under development players can explore it in a free-camera mode, by feet as well as in vehicles such as planes, boats and cars and spawn user-made objects such as houses and (usable) vehicles. In game the user can blend in an embedded Google Maps of real Earth that is synchronized with the current camera position.