A choropleth is a type of thematic map that uses color or shading to represent data values across specific geographic areas, such as countries, states, or regions. Each area is filled with a color corresponding to the value of a particular variable, like population density or income levels. This visual representation helps to easily identify patterns, trends, and disparities in the data across different locations. Choropleth maps are widely used in fields like geography, statistics, and Social Sciences to communicate complex information effectively.