This example demonstrates how to use the JavaScript `map` function on an array. It defines an array `[10, 20, 30]` and applies `map` to multiply each element by 2, logging the result to the console. The React application does not render any visible content; instead, the example focuses on the logic of transforming data with `map` within a React component structure. It uses React and ReactDOM from the UMD builds, with all logic contained in the `index.js` file.