This example visualizes a hierarchical tree of car companies and their brands, with the root “Car Company” branching into groups like General Motors, Volkswagen, and Stellantis. The code uses D3.js v3’s `d3.layout.tree` and `d3.svg.diagonal` to compute and draw the node-link layout. Nodes appear as white circles with steelblue strokes, connected by orange curved links, and each node’s name is displayed in sans-serif text. SVG rendering and a 750ms animated transition are implemented, with static data defined inline in the script.