This interactive bar chart displays the top 10 most populous countries in 2020 according to the United Nations World Population Prospects 2019. The visualization loads CSV data via `d3.csv` and uses React with hooks (`useState`, `useEffect`) to manage asynchronous data fetching and rendering. D3 v5 constructs the scales: `d3.scaleBand` for countries on the y-axis and `d3.scaleLinear` for population on the x-axis. The SVG output includes gridlines and tick labels via `xScale.ticks()`, with bars drawn as `rect` elements.