Answer:
Downward communication:
Communication in the first place, flows downwards. That is why, traditionally this direction has been highlighted or emphasized. It is based on the assumption that the people working at higher levels have the authority to communicate to the people working at lower levels.
Upward communication:
The function of upward communication is to send information, suggestions, complaints and grievances of the lower level workers to the managers above. It is, therefore, more participative in nature.
Lateral or horizontal communication:
This type of communication can be seen taking place between persons operating at the same level or working under the same executive. Functional managers operating at the same level, in different departments, through their communication, present a good example of lateral communication.
Diagonal or crosswise communication:
Diagonal or crosswise communication takes place when people working at the same level interact with those working at a higher or lower-level of organizational hierarchy and across the boundaries of their reporting relationships.