A world map visualization shows the geographic distribution of COVID-19 cases, allowing users to toggle between confirmed cases, deaths, and recoveries via a dropdown menu. Country boundaries are rendered with d3.geoPath, while proportional circles sized with d3.scaleSqrt mark outbreak severity at each nation’s centroid. Data from a CSV file is joined to TopoJSON country geometries using a country code key. The map supports zooming and panning via d3.zoom, and includes custom color and size legend components built with D3’s selection and scale APIs.