This visualization shows a hierarchical tree diagram with collapsible nodes, rendered as boxes connected by links. Each node displays a label and is colored based on the `gender` attribute from the JSON data—blue for male, green for female. The tree uses D3.js v3 layout functions to position nodes, with SVG rectangles for nodes and paths for links. Clicking a node triggers an animated collapse or expansion of its children, updating the layout dynamically. The example is implemented as a React component and loads data from an external JSON file using `d3.json`.