What is the difference between a dot map and a choropleth map?

Dot maps use dots to represent a stated amount of some phenomenon within a political unit. Using a scale equating one dot with 1,000 people, 12 dots in one area would represent 12,000 people living in that area.

On a choropleth map each political unit is fulled in with a distinguishing color or pattern but instead use lines to join points of equal value across the mapped area.

So in short, one map uses dots, and the other uses lines.