This example visualizes a small network of Facebook friends, where nodes represent individuals and links represent connections between them. The graph uses a force-directed layout to position nodes, with link thickness proportional to the connection weight. The visualization is built with D3.js v4, using the `d3.layout.force` API for the layout simulation and SVG rendering. Node labels are placed beside each circle, and the data is loaded from a local JSON file containing node names and link weights.