This example visualizes the top 10 most populous countries as a horizontal bar chart, using population data from the United Nations World Population Prospects 2019. The visualization renders bars via SVG `<rect>` elements, with axes built from D3 v5 scales (`scaleBand` and `scaleLinear`) and React components for the axes and marks. The code also includes a custom tooltip via an SVG `<title>` element and uses D3’s `csv` loader to fetch the data.