A horizontal bar chart displays the 2020 populations of 30 countries, loaded from a remote CSV via `d3.csv`. The visualization uses React components to render an SVG, with `d3.scaleBand` for the categorical y-axis and `d3.scaleLinear` for the population x-axis. Axis labels and tick marks are generated with custom `AxisBottom` and `AxisLeft` components, and each bar includes a native SVG `<title>` tooltip showing the formatted population value.