Justin O'Beirne lays out years worth of research on mapping technologies in his essay Google Map's Moat. O'Beirne reveals,"Over the past year, we’ve been comparing Google Maps and Apple Maps [...] The biggest difference is the building footprints: Google seems to have them all, while Apple doesn’t have any. [...] The buildings are a new thing, and I’ve been watching Google gradually add them over the past year."

With plenty of map screenshot GIFs, O'Beirne illustrates how Google has integrated architecture (including sheds, trailers, garages, etc.) with fairly accurate architectural detail just in the past year. Compared alongside Apple and other mapping technologies, Google is far ahead of the game.  

Google is also using this data to create AOI's, Areas of Interest, on it's mapping service. Using it's building footprint data collected from satellites and the function of those buildings from street view cars, Google has now determine which areas are "areas of interest". You may have noticed AOI's pop up on your Google maps app this year—they are the orange shaded areas. 

Dig into Justin O'Beirne's full essay here. Seriously, it is worth a read.