There are 5 main types of communication flows in an organization: downward, upward, lateral/horizontal, external, and diagonal. Downward communication flows from higher to lower levels and is used by managers to transmit work information to employees. Upward communication flows from lower to higher levels and provides feedback and allows employees to share ideas. Lateral communication occurs at the same levels and coordinates work between departments. External communication occurs between an organization and outside entities. Diagonal communication bypasses vertical/horizontal channels and allows direct communication between different departments.