This bar chart displays the population of the top 20 countries in 2010, with the data loaded from a CSV file using D3’s `csv` function. The visualization uses React with reusable axis components (`AxisBottom`, `AxisLeft`) and a `Marks` component that renders SVG rectangles. D3’s `scaleBand` and `scaleLinear` position the bars, while `format` abbreviates tick labels from units like “G” to “B”. Hovering a bar reveals its exact value via a native SVG `<title>` tooltip.