I can create Campaigns for every certain city we wanted to focus or exclude them. That can happen by the city name, by the zip codes or radius on miles. Of course if I wanted to have all overall US or world it is possible too, but most scenario wont bring ROI for that big area.
I can make some specific price campaigns for some locations different price or content than other locations! or People who interested services in my place but they are searching from somewhere again I can control that one too! Or NewYork more competition than florida so I can raise my bid some % more or less for better performance, rank and conversion rate.