This bar chart displays the ten most populous countries in the world for 2020, using horizontal bars sorted by population. The visualization is built with React and D3 v5, using `scaleBand` for the categorical y-axis and `scaleLinear` for the numeric x-axis. Data comes from the United Nations World Population Prospects 2019, loaded via `d3.csv`. Bars are rendered as SVG `<rect>` elements, with D3’s `format` for tick labels and a tooltip on each bar.