This example shows a bar chart of the ten most populous countries for 2020, using data loaded from a CSV file of UN population estimates. The visualization renders as a series of horizontal rectangles whose lengths correspond to each country’s population. Built with React for component structure and D3 utilities for data loading (`d3.csv`) and scaling (`scaleBand`, `scaleLinear`), the chart is drawn as an SVG. The code uses React hooks (`useState`, `useEffect`) to fetch and store the data, then maps it directly to `<rect>` elements.