A choropleth map displays countries of the world colored in light green, with a blue sphere representing the globe and black borders between nations. The visualization uses `d3.geoNaturalEarth1` projection and `d3.geoPath` to render geographic features from TopoJSON data, while country names come from tab-separated values (TSV) data. Interactive zooming is implemented with `d3.zoom`, converting events to SVG transforms. Hovering over a country changes its fill color to red through CSS `:hover` styles, and tooltips with country names appear via SVG `title` elements.