This example visualizes a small social network with six nodes and five weighted links, displaying names as labels and circle nodes colored green. The force-directed layout uses `d3.layout.force` from D3 v4, with gravity, charge, and distance parameters controlling node positioning, while link thickness reflects the `weight` attribute. Data is loaded from a local `data.json` file, and the SVG rendering includes drag interaction via `force.drag` and tick-based updates for link coordinates and node transforms.