This world map visualizes global population distribution by income group, using color to encode each country's economic classification. The map is rendered with D3 v5’s `d3.geoMercator` and `d3.geoPath`, projecting GeoJSON country boundaries from the world-atlas package. A color legend, built with custom D3 code, maps income categories to a sequential red color scale (`d3.schemeReds`), while interactive zooming is enabled via `d3.zoom`. Population data from the included CSV is not directly displayed but informs the visualization’s narrative.