This example displays a small social network of six named individuals organized into three groups, with weighted links connecting them. It uses a force-directed layout created with `d3.layout.force` (from D3 v4), rendering nodes as blue circles and links as black lines whose stroke-width reflects each connection’s weight. Node labels appear in red text, and the graph is drawn as an SVG element sized 950 by 500 pixels. The data comes from a local `data.json` file containing nodes and links with weight attributes.