A horizontal bar chart displays the 2010 population for 20 countries, with each bar length proportional to population. The visualization uses React components (Marks, AxisBottom, AxisLeft) to render SVG rectangles, with d3.scaleBand for the categorical y-axis and d3.scaleLinear for the continuous x-axis. Data loads via d3.csv from a GitHub-hosted CSV file, and the bars include native SVG tooltips showing formatted population values using d3.format.