Choropleth Map

A Choropleth map is a map that shades geographical areas according to statistics of each particular area.  The shades of color can vary from any colors the cartographer decides to use for that particular map.  This choropleth map shows the percentage of Hispanic or Latinos in the U.S. in 2000.  By looking at this map, you are able to see that the darker shaded red shows the largest percentage in that region. 
http://www.bagofnothing.com/2008/07/map-gallery-of-ethnic-groups-in-the-united-states/