This network graph visualizes Facebook friendships between countries in Southern Africa, using a node-link diagram where circles represent countries and connecting lines represent relationships weighted by their strength. The visualization is built with D3.js (v4) and uses a force-directed layout via `d3.layout.force()` with gravity, distance, and charge parameters to position nodes. The SVG is rendered with circles and text labels, with node size and color determined by the group field in the loaded JSON data, while link thickness scales with the `weight` attribute. The algorithm updates node positions on a tick event, allowing for interactive dragging of nodes.