This example visualizes a restaurant business hierarchy as a tree graph, with nodes representing categories like Location, Cuisine Type, and Price Range, each branching into specific subcategories. Node size encodes a numeric value, while stroke and fill colors differentiate types and levels. The code uses D3 v5’s `d3.tree()` and `d3.hierarchy()` to compute layout, rendering SVG paths for links and circles for nodes. Data is hardcoded in JavaScript, with styling applied via CSS classes.