This horizontal bar chart displays the populations of 20 countries in 2020, using United Nations population data. The chart is built with React and D3 v7, where each country’s population is represented by an orange horizontal bar, sorted from largest to smallest. The visualization uses D3’s `scaleBand` and `scaleLinear` to map categorical and numerical data, with SVG `rect` elements for bars and custom axis components. Populations are shown in billions using D3’s `format` function, and tooltips display precise values via SVG `<title>` elements.