This example visualizes a small social network of nine individuals, showing connections as links whose thickness encodes the weight of the relationship. The graph layout is computed by a force-directed algorithm (d3.layout.force), which positions nodes with charged particles and supports interactive dragging via force.drag. Nodes are rendered as gray circles with name labels, while links are drawn as gray lines (SVG line elements). Data comes from the graph.json file, defining node names, group assignments, and edge weights, with the simulation updating positions on each tick event. The visualization uses d3.json to load data and d3.select to append the SVG canvas.