This chart visualizes the 2010 population of the top 20 countries by country, presented as a horizontal bar chart. The code uses React to construct the SVG elements, with D3's `scaleBand` and `scaleLinear` to map data to the x and y axes. The data is fetched live from a CSV file using D3's `csv` function. Blue axis ticks and green bars are styled via CSS, with a tooltip showing the formatted population on hover.