B base map A raster map provided directly from a provider to your browser through an Internet connection. These maps can be used either by themselves or as a base on which to overlay map data from a map service. Microsoft Bing Maps for Enterprise and Google Maps are examples of base map providers. buffer An area of specified distance (radius) in all directions around a feature on a map. Buffer tool A tool to define buffer areas around an object, such as a map feature or user-defined shape. See buffer.