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[CptLucky8]

I believe this is already explained in great details and voted more than 600 times here:

Scenery Gateway System - World Hub

Now that the voting feature is implemented, I’d like to propose a worldwide Airport/Scenery/POI’s Gateway system to be implemented so that the community can contribute and create scenery for the sim. How it works Community members make scenery for an airport, or a statue or some islands. They then upload them to a central repository. After it’s approved for quality by the folks at Asobo, the scenery is then updated as part of the base sim package. The scenery is made available to do…

and here:

X-Plane Scenery Gateway