A world map renders country boundaries and graticules from World Atlas TopoJSON, with city points sized by population using a square-root scale. Built with React and D3 v5, it uses `geoNaturalEarth1` projection, `geoPath`, and `geoGraticule` to draw shapes, while circles are positioned by projecting latitude and longitude coordinates. The SVG output is styled with a light gray land fill and semi-transparent teal city markers.