Nodes in a network experience interactions; these are behavior-based ties like talking with each other, attending an event together, or working together. If you chat online with a prospective dating partner on Match.com, you are a node engaging in an inter action with another node (hopefully a node, but not a nerd). And, if that actually works out and you participate in an online forum that shares experiences about wedding photographers in your area, you engage in interactions with other nodes who are also getting hitched. Interactions are participative in nature; they are shared activities among members in the network.