This example shows a choropleth map of poverty rates by U.S. county, with color intensity indicating the poverty value for each county. It uses d3.geoPath to render the topojson-based county boundaries, while d3.scaleThreshold and d3.schemeGreens map the data values to a green color ramp. Interactive tooltips display the county name and poverty value on hover, and a color legend is added via the d3-legend library. The data is loaded from a CSV containing poverty attributes per county.