Choropleth Map

http://my.ilstu.edu/~jrcarter/Geo204/Choro/Tom/

A choropleth map is a thematic map that displays predefined aerial units. These map types display one variable of data and use a color gradient to indicate intensity.  The data can divided through either natural breaks, equal intervals, or quartiles. The choropleth map above shows the percent of person who are Spanish or Latino in Florid, by county. The color gradient uses different shades of green to indicate increasing values.