It seems that google has a more coherent theory of how users use maps at different zoom levels. At the outermost zoom, physical geography is emphasized : terra

It seems that google has a more coherent theory of how users use maps at different zoom levels. At the outermost zoom, physical geography is emphasized : terrain shows prominently, and political boundaries at the national level with hints of state boundaries. Zoom in farther, and political bondaries are more emphasized and physical features less. States are named and some cities. Zoom in farther and you start to reach the domain of navigation. Large roads are prominent and labelled, as are some cities. Zoom in farther and more roads are labelled, as well as rail/metro stops and some landmark destinations. At the highest levels of zoom, finally it transitions to destinations and foot-navigation as the focus. Apple has a similar progression, but with less coherence. It emphasizes cities/neighborhoods more at the expense of road labels. And landmarks and destinations appear at lower zoom levels, also at the expense of road labels. Rail/metro stations are much less prominent.