The document discusses the nature and types of organization structures. It describes a formal organization as having well-defined jobs, authority, and accountability. An informal organization arises spontaneously from interpersonal relationships. The document contrasts key differences between formal and informal organizations, such as how formal organizations are deliberately created by management to achieve objectives, while informal organizations emerge to provide social and psychological satisfaction. Formal organizations are larger in size and follow rules and hierarchies, whereas informal organizations are smaller and communication flows through informal channels.