This family tree visualization uses a hierarchical tree layout to display a root node ("Sandeep") with two children, each branching into their own leaf nodes. The code constructs a D3.js tree using `d3.tree()` and `d3.hierarchy`, then renders the structure as SVG paths and circles. Node radius is scaled by the data’s `value` attribute, while stroke and fill colors are driven by the `type` and `level` properties within the JSON source. Curved links between nodes are drawn as cubic Bézier paths via the `attr("d", ...)` string concatenation.