A horizontal bar chart displays the population of the top 10 countries in the year 2000, using a d3.scaleBand for the y-axis and d3.scaleLinear for the x-axis. The React app loads CSV data from a GitHub repository via d3.csv, then renders SVG rectangles through the Marks component, with axes built by AxisBottom and AxisLeft. Populated bar values appear as native tooltips using SVG title elements, while the x-axis labels are formatted with d3.format to abbreviate numbers (e.g., "B" for billions).