This visualization uses a natural Earth projection with D3’s `geoNaturalEarth1` and `geoPath` to draw world landmasses, graticules, and sphere outlines, overlaid with circles sized by city population via `scaleSqrt`. The React component loads World Atlas TopoJSON for boundaries and a CSV of HIV/AIDS prevalence data for cities, mapping each city’s longitude and latitude to screen coordinates. Semi-transparent teal circles highlight population distribution, while the underlying choropleth styling uses SVG paths and CSS classes. Data sources include the World Atlas TopoJSON and a Simplemaps-derived cities dataset.