A network editor allows users to create and modify directed graphs through direct manipulation. Nodes can be dragged to reposition them, with dragged nodes becoming fixed, while links are added by selecting source and destination nodes. The example uses React with D3 v4’s `d3.forceSimulation` for layout, applying link, center, and collision forces. SVG rendering includes interactive node rectangles and link lines, with keyboard shortcuts for editing and buttons for configuring states and conditional probability tables.