This interactive tree diagram visualizes the hierarchy of two car brands, Tesla and Toyota, and their respective models, using a collapsible node-link layout. Rendered with SVG in a React application using D3 v3, the visualization color-codes nodes by type and includes tooltips that appear on hover. The layout is computed with `d3.layout.tree`, and user interaction supports zooming and panning via `d3.behavior.zoom`. Data is loaded from an external JSON file specifying the brand, model, and relationship structure.