Final answer:
The network of unofficial relationships among an organization's members is known as the informal structure, which is an important aspect of organizational dynamics that exists alongside the formal, bureaucratic structure of an organization.
Step-by-step explanation:
The network of unofficial relationships among an organization's members is referred to as the informal structure. This contrasts with the formal structure of an organization, which consists of the official, bureaucratic aspects such as hierarchies, formal rules, and clearly defined roles. Informal structures involve the social networks, relationships, norms, and unwritten rules that develop organically among people within the organization. These informal networks can significantly influence how work gets done, as they facilitate communication and can sometimes bypass formal procedures.
Formal organizations are characterized by their large size and impersonal nature. Bureaucracies within these organizations typically have a clear hierarchy of authority, division of labor, explicit rules, and a high level of impersonality. However, within these formal settings, informal structures can emerge and play a crucial role in the day-to-day operations and dynamics of the organization.