A social network graph visualizes friend connections between people, with each person as a circular node and their relationships as lines with arrow markers. The graph uses a force-directed layout via `d3.forceSimulation`, with `d3.forceLink` controlling link distances and `d3.forceManyBody` for repulsion between nodes. Node colors are uniform light green, and text labels display names. Users can drag nodes to reposition them, and hovering changes the node stroke. The data comes from a JSON file containing nodes and links, rendered as SVG elements.