This example shows a horizontal bar chart of the 20 most populous countries in 2010, with population values on the x-axis and country names on the y-axis. It uses React with D3 v5’s `scaleBand` and `scaleLinear` to position bars, while custom `AxisBottom` and `AxisLeft` components render tick marks and labels. Data is loaded asynchronously from a CSV via `d3.csv` and `useEffect`, with population converted from thousands. A `Marks` component draws each rectangle and includes a `title` element for hover tooltips.