Adding tile overlays to maps
Google Maps has a selection of base maps as street maps and satellite imagery, which we discussed in the previous chapter; we will now discuss how additional base maps can be introduced to the Google Maps interface.
We can also use tiled map services as overlays to the base maps. By overlay, you can think of a separate sheet of map tiles put over the base maps. You can observe the details of the overlaid layer together with the base map. Examples of overlay layers might be of the boundaries of areas of interest, special POIs that are not found in the Google Maps' base maps, statistical results to be presented with aerial or point styling, and so on.
The tile map services that are used as base maps can technically be used as overlays in the Google Maps JavaScript API. However, using these tile map services (such as OpenStreetMaps) as overlays results in blocking the original base maps of Google Maps, as there would be no blank space in the map of overlaid tile map...