GeoGraphics are graphical objects, that does not store the graphics information in screen space, but in geographical coordinates. Therefore GeoGraphics must be placed on GeoLayers to work properly.
Note: As GeoLayers are always children of a map layer. When the map is changed all GeoLayers are notified via the 'adaptTo(map)' method.
The geolayers forward this 'adaptTo' to all children that are GeoGraphics. Which adjust their so called 'point' data to the new map.
GeoPoint is a single coordinate in the map.