This example shows a horizontal bar chart of the top 10 most populous countries in 2020, using React to render SVG elements while D3 provides scales and data loading. It uses `d3.csv`, `scaleBand`, `scaleLinear`, and `max` to process the UN Population 2019 dataset and compute the chart layout. Ticks from the x-axis are drawn manually with lines and text, while y-axis labels and rectangles are mapped directly from React state.