A Shapefile (Esri Shapefile) is a vector format that represents geographic data (e.g., rivers, lakes, and countries) using geometries (e.g., points, polylines, and polygons). Data in this format is usually stored in two files:
a .shp file that contains data about geometries;
a .dbf file that contains data associated with geometries from the corresponding .shp file.
When data is loaded from a Shapefile, the Map control generates a collection of vector items objects stored in a VectorLayer.
Note that in this case, data from a .dbf file is stored as attributes in each vector item object. This approach allows you, for instance, to use this data to colorize shapes or display supplementary information in shape tooltips.