A horizontal bar chart displays the ten most populous countries in 2020, drawn as SVG rectangles. The React component loads CSV data via D3’s `csv` utility, then uses `scaleBand` for country positions and `scaleLinear` for population values. Grid lines and axis labels are generated from the x-scale’s `ticks()`. The chart updates reactively through React’s `useState` and `useEffect` hooks, with D3 v5 handling data loading and scaling while React manages the SVG rendering.