This example displays the top 10 most populous countries as horizontal bars, with country names on the left and population values formatted in billions along the bottom axis. Built with React and D3 v5, it uses `scaleBand` for the categorical y-axis, `scaleLinear` for the continuous x-axis, and SVG `<rect>` elements for the bars. Data comes from the United Nations World Population Prospects 2019, loaded via `d3.csv` and sorted to the ten largest populations. Native SVG `<title>` elements provide hover tooltips with formatted population values.