This document discusses different types of communication in organizations. It begins by defining formal communication as flowing along prescribed channels that members must follow, including vertical and horizontal communication. Vertical communication involves communication between managers and their subordinates or superiors. Downward communication flows from superiors to subordinates to give directions, policies, and performance updates. Upward communication flows from subordinates to superiors and provides feedback, addresses grievances, and offers suggestions. Horizontal communication occurs between peers at the same level and facilitates coordination. The document also discusses informal communication, also known as the grapevine, which occurs through unofficial channels and transcends formal lines.