This example visualizes CSV data about UN world population as a grid of solid red rectangles, where each cell corresponds to a row in the dataset. Built with React and D3, it uses the `d3.csv` function to load and parse the external CSV file. React’s `useState` and `useEffect` hooks manage the asynchronous data loading, rendering a “Loading…” message until the data arrives, then mapping each record to a flex-wrapped div with computed width and height dimensions.