This example displays a vertical bar chart of the top ten countries by 2020 population, using the UN Population dataset loaded via D3’s `csv` utility. React manages the component state and renders SVG `rect` elements, while D3’s `scaleBand` and `scaleLinear` compute the bar positions and heights. The chart resizes to the full browser window, and bars extend upward from the bottom edge with the y-axis inverted to match the data scale. D3 v6 and React 17 are loaded from CDNs, and the visualization updates after an asynchronous data fetch.