This example shows the 20 most populous countries in 2020 as a horizontal bar chart, with country names on the y-axis and population values on the x-axis. The bars are rendered as SVG rectangles using React components, with scales created via `d3.scaleBand` and `d3.scaleLinear`. Axis ticks are formatted using `d3.format` to convert values to billions. The data is loaded from a CSV file using `d3.csv`, and the chart includes tooltips via SVG `<title>` elements.