This example visualizes a network of nodes and links loaded from a local JSON file, where each node represents an entity with a name, group, and centrality value, and links connect them with betweenness scores. It uses D3 v3’s `d3.layout.force` to simulate a force-directed layout with a fixed distance of 300, weak charge, and zero gravity, rendering nodes as GitHub favicon images with labels and links as gray SVG lines. The simulation updates node positions and link coordinates on each tick, constraining movement to the 960×500 viewport.