This example shows a horizontal bar chart of the ten most populous countries, using United Nations population data for 2020. It loads the data with `d3.csv` and renders each country as an SVG `<rect>` element. React hooks (`useState` and `useEffect`) manage the asynchronous data loading, while `d3.scaleBand` and `d3.scaleLinear` map country names and population values to pixel positions and bar widths. The visualization updates from a loading state to the final chart once the CSV resolves.