This example visualizes a small conceptual social network of six people connected by family, friendship, and school relationships. The code builds the graph using D3 v7 with a force-directed layout via `d3.forceSimulation`, `forceLink`, `forceManyBody`, and `forceCenter`. Nodes are drawn as colored SVG circles scaled by group category, with labels beside each, and links rendered as lines. Draggable nodes reposition the simulation, which recalculates positions on each tick.