This horizontal bar chart displays the top 30 countries by 2020 population, sorted in descending order. The visualization uses a linear x-scale for population values and a band y-scale for country names, with teal bars rendered as SVG rectangles in a React component. Data is loaded via `d3.csvParse` from a GitHub gist, with axis ticks formatted in millions. The code demonstrates React state management with `useState` and `useEffect` hooks alongside D3’s `scaleLinear` and `scaleBand` APIs.