The example shows a horizontal bar chart displaying the top 10 countries by population in the year 2000, using a clean margin-based layout. It loads CSV data from a GitHub gist via `d3.csv`. The chart uses React hooks (`useState`, `useEffect`) for state management and D3 v5's `scaleBand` and `scaleLinear` to map countries to y-positions and population values to bar widths, rendered as SVG `<rect>` elements within a translated `<g>` container.