A force-directed network graph visualizes WiFi-connected devices in a home, with nodes representing devices like a router, laptop, phone, and smart TV, colored by device type via `d3.scaleOrdinal` and `d3.schemeCategory10`. The layout is computed using `d3.forceSimulation` with `d3.forceLink`, `d3.forceManyBody`, and `d3.forceCenter` forces, rendered as SVG circles and lines. Data is loaded from `wifi_network.json`, and nodes are draggable, with labels positioned beside each circle as the simulation ticks.