This bar chart visualizes the ten most populous countries using data from the UN’s 2019 World Population Prospects. It displays each nation’s estimated population along a horizontal axis, with country names on a vertical band scale. The visualization uses React components with D3’s `scaleBand`, `scaleLinear`, and `max` to compute layout, rendering SVG rectangles as marks. Interactive tooltips appear via SVG `<title>` elements, while axis ticks are formatted with `d3.format`.