A horizontal bar chart displays the populations of thirty countries in 2020, sourced from a CSV file. Built with React and D3 v5, the visualization uses `scaleBand` for the categorical y-axis, `scaleLinear` for the quantitative x-axis, and `Marks` to render SVG rectangles. Axis components generate ticks and labels, while a custom tick formatter converts values to billions. A tooltip is provided via SVG `<title>` elements.