This bar chart displays the populations of 20 countries using data from the UN Population 2019 CSV. The visualization encodes values horizontally with SVG rectangles, where the x-axis uses a d3.scaleLinear and the y-axis uses a d3.scaleBand. Data is loaded via d3.csv, and the chart is rendered through React components managing state with useState and useEffect. The example uses React 17, D3 v7, and SVG rendering.