This choropleth map visualizes world population data by country income group, using color intensity to show distribution across regions. The visualization supports interactive zooming and panning, with hover effects highlighting individual countries. Built with D3 v5, it uses `geoNaturalEarth1` projection, `geoPath`, and `geoMercator` for map rendering, while `scaleOrdinal` with `schemeReds` maps income categories to colors. A dynamic color legend animates its circles using transitions. Country boundaries and income classifications come from the World Atlas TopoJSON dataset, with a hover tooltip displaying country names.