This choropleth map displays global income groups using a color scale applied to each country’s territory. The visualization employs d3.geoPath with a natural Earth projection to render the GeoJSON features, while d3.scaleOrdinal and schemeSpectral map income categories to colors. A custom color legend, built with select and merge, appears on the left. The map supports zooming via d3.zoom, and hovering highlights countries in red. Data comes from the world-atlas TopoJSON and TSV files, processed with topojson.feature.