A GitHub repository's contributor activity is shown as a network graph, where nodes represent authors and links connect those who committed to the same repositories. Force-directed layout positions the nodes using `d3.forceSimulation`, `d3.forceLink`, and `d3.forceManyBody`, with the author names and commit counts sourced from a CSV file. The visualization is rendered as an interactive SVG, allowing nodes to be dragged and repositioned, with labels updating in real time.