This example displays a horizontal bar chart of the top 20 countries by population in 2010, read from a remote CSV file via d3.csv. The React app maps the data to SVG rectangles using d3.scaleBand for the y-axis and d3.scaleLinear for the x-axis, with axes built from d3.scaleBand.ticks and tick formatting via d3.format('.2s'). Hovering reveals the population value in a tooltip through the SVG `<title>` element.