This example visualizes global population data from a 2019 UN dataset, displaying each country as a rectangle in a bar-chart-like SVG layout. The chart maps country names to vertical positions using a D3 scaleBand, though the rectangles are left with placeholder width and height values. The code loads the CSV data with D3’s `csv` utility and manages asynchronous data fetching with React hooks (`useState`, `useEffect`). React renders the SVG elements directly, while D3’s scaling functions handle the band positioning for each row.