Throughout the history of cartography, the effective use of maps means understanding a series of abstract symbols drawn on the plane and then connecting these symbols with various three-dimensional features of the local environment, so as to successfully determine their own location. But not all ordinary people can do this and not long ago, the map itself was a scarce artifact, some of which were militarily sensitive secrets. But the map that can be seen on the phone screen changes all that.
The most important part of this passage is that smart phones have greatly improved the quality of human life.