This example visualizes the top 10 countries by projected 2020 population as a horizontal bar chart, with country names on the y-axis and population scaled along the x-axis. It loads data from a CSV URL using the D3 `csv` function and stores the parsed result in React state via the `useState` and `useEffect` hooks. The bars are rendered as SVG `<rect>` elements, with positions and widths computed using D3’s `scaleBand` and `scaleLinear`. React manages the component lifecycle, displaying a loading message until the data arrives.