The document summarizes James Grunig's four models of public relations: 1) The press agentry model uses one-way communication and persuasion to influence audiences. 2) The public information model also uses one-way communication to distribute information about the organization. 3) The two-way asymmetric model uses two-way communication to research publics and persuade them to align with the organization's interests. 4) The two-way symmetric model promotes mutual understanding between an organization and its stakeholders through two-way communication and negotiation.