This example shows the data loading lifecycle in a React and D3 application, displaying a text summary of a CSV dataset’s size, row count, and column count. It demonstrates asynchronous data fetching using D3’s `csv` utility, where the result is stored in React state via `useState` and `useEffect`. Once loaded, the `message` function formats the file size, row, and column details. The visualization uses ReactDOM to render the output, with D3 v5 and React 16.9.0, pulling data from a local CSV file about fat supply quantity.