The actor is the central figure in the collaboration diagram because it initiates the interaction. Each actor has a unique role and name. One actor starts the use case in this case. The link is an example of the association because it connects the objects and actors. It depicts a relationship between the things through which messages are transmitted. A solid line is used to represent it. The link allows an object to connect with or navigate another object, so message flows are associated with connections. Collaborations are used when depicting the relationship between things is critical. The sequence and collaboration diagrams both represent the same information but differently. Collaboration diagrams are ideal for analysis.