Thematic Map

A thematic map is a type of map that is designed to show a theme for a specific geographic area.  Some of these themes include physical, social, political, cultural etc.  This particular thematic map portrays the number of mortgage origination's for the U.S. in 2008.  The warm colors show the highest amount of mortgages and cool colors show lowest amount mortgages in that particular region.
http://mortgagedataweb.blogspot.com/2009/06/fha-mortgages-thematic-map.html