This example displays a hierarchical tree visualization of Indian food items, organized by region and course. The data is embedded as an array of objects showing five dishes, which is converted into a tree structure using a custom `buildHierarchy` function. The visualization uses `d3.hierarchy` and `d3.tree` to compute the layout, with `d3.linkHorizontal` generating curved paths for the links. Nodes are rendered as SVG circles with text labels, positioned via the `transform` attribute, and styled with CSS classes.