People we know in one group can assist us in accessing other groups of which they are already members but to which we do not belong. Networking can help people get information, find jobs, find business opportunities, find others interested in the same hobbies, etc. Formal organizations are large, secondary groups that are organized to achieve goals efficiently. They have many people who are quite specialized in what they do. Try to apply Etzioni's classifications.
Bureaucracies are the most common kind of formal organization in American society.
Hierarchy of positions, 3. Written rules and regulations, 4. Technical competence as the chief criterion for hiring and promotion, 5. Impersonality, and 6. Formal, written communication.