A horizontal bar chart displays population figures for twenty countries in 2010, using green rectangles to represent values on a linear scale. The chart is built with React and D3 v5, using `scaleBand` for the categorical y-axis and `scaleLinear` for the quantitative x-axis. Data is loaded from a remote CSV via `d3.csv`, and axes and marks are rendered as SVG components with formatted tick labels converting gigabytes to billions.