A vertical bar chart displays the top ten countries by 2020 population, sourced from a UN_Population_2019 CSV file. The React component uses `useState` and `useEffect` to load data via D3’s `csv`, then renders SVG rects for bars. Axes are drawn manually with D3 scales (`scaleBand`, `scaleLinear`) and tick marks, including rotated country labels. The visualization updates the chart to fit the window dimensions, with bars positioned using `xScale` and `yScale` and heights derived from population values.