A world map visualization displays the top 10 most populous countries as a bar chart using SVG rendering with React. The chart plots temperature data over time, with D3 scales (scaleTime, scaleLinear) and axes built from custom AxisBottom and AxisLeft components. The Marks component uses d3.line with curveNatural to draw a smooth path, while circles represent individual data points with tooltips. Data comes from the United Nations World Population Prospects 2019 via a JSON URL fetched using d3.json.