# 4-8-3. Network diagrams

Network diagrams are used to show how the different activities that make up a project ( or sub-project) are connected together. There are two different types of network diagrams – Activity-on-Node (AON) diagrams and Activity-on-Arrow (AOA) diagrams. Click on the links below to see an example of each type of diagram. We will learn how to construct these diagrams when we talk about project scheduling.

AON-diagram

In the AON diagram the tasks that make a up project or sub-project are represented as the nodes of the diagram and the arrows signify the completion of those tasks.

AOA-diagram

In the AOA diagram, the project tasks are represented as arrows and the nodes represent the beginning or completion of tasks.