This example demonstrates the Margin Convention for bar charts, showing the top ten countries by 2020 population as horizontal bars. It loads data from a CSV file using `d3.csv`, then uses React state and the `useEffect` hook to fetch and store the data. The chart is rendered as SVG, with `d3.scaleBand` mapping countries to the y-axis and `d3.scaleLinear` mapping population to the x-axis. A margin object defines padding, and the inner chart area is translated accordingly using an SVG `<g>` transform.