Today we’re introducing the latest version of Google Earth, our interactive digital atlas. [emphasis mine]
It’s interesting to me that Google labels Google Earth as an “atlas”—not because of the terminology (it certainly seems to fit the definition of an “atlas”)—but rather because Google seems to be labeling it as the company’s sole “atlas”. (Notice that they didn’t say “one of our” interactive digital “atlases”.) Apparently, Google Maps is not also an “atlas”.
This actually makes quite a bit of sense. For instance, I can’t ever recall seeing an “atlas” that didn’t denote national capitals. While Google Earth (aka Google’s “atlas”) certainly does, Google Maps doesn’t. Consider also that Google Earth shows many secondary political boundaries, like county borders, that are entirely missing from Google Maps. Indeed, in many ways, Google Earth actually is a better “atlas” than Google Maps.
In other ways, though, Google Earth is an inferior “atlas” to Google Maps. Case-in-point: Google Earth’s sparse and uneven city labels. Cities with populations of under 20,000, for instance, typically don’t appear until you’re in full view of their street grids. In my own experience, this makes navigating Google Earth quite difficult, and it’s incredibly easy to get lost while browsing the maps. (I’m not alone in this view.)  Previous comments about Bing’s sparse city labels could easily be applied Google Earth—doubly so, in fact. You simply have to zoom-in way too far before most smaller cities appear on the maps.  Besides that, most of the information on Google Maps’s “Terrain” maps (elevation contours, terrain coloring, etc.) seems to be entirely missing from Google Earth. And consider that Google Earth doesn’t even have Google Maps’s diversity of city “dots”: unlike on Google Maps, all of Google Earth’s cities (other than its capitals) have the exact same city “dots” and label sizes, precluding meaningful comparisons amongst cities.
All this aside, I don’t understand why Google Maps can’t also be an “atlas”. Why show information like country capitals and county labels on Google Earth, but not on Google Maps? I think there’s an incredibly easy (and elegant) solution to this, and I don’t understand why Google hasn’t implemented something similar to it. (They could even call it an “Atlas” tab.) 
 For a direct comparison of the city label densities on Google Earth and Google Maps, click here.
 Given how “advanced” Google Earth is, I’m surprised users are unable to customize the maps’ city label densities.
 Consider also that Google Maps, as opposed to Google Earth, is generally more accessible to greater number of people. There’s nothing to install; all you need is a somewhat-modern browser.