A horizontal bar chart displays the populations of ten countries for the year 2000, with each bar's length proportional to its population value. The chart uses a green fill for the bars and blue axis tick marks. Built with React and D3 version 5, the visualization uses `scaleBand` for the categorical y-axis, `scaleLinear` for the quantitative x-axis, and renders as SVG. Population data is loaded from a remote CSV file using `d3.csv`, and D3's `format` function converts large numbers to a compact "B" (billion) notation for axis labels and tooltips.