This example presents a reference world map and a choropleth map showing internet users per 100 people in 2015, both rendered as SVG using D3 v7 and TopoJSON. The code employs `d3.geoNaturalEarth1` for the projection, `d3.geoPath` for generating map paths, and `d3.geoGraticule` to draw latitude and longitude lines. Country boundaries come from the world-atlas TopoJSON file, with each country colored by its rate in the second map, accompanied by a legend.