Node is a space, where you define, who will send what to whom, what he will be sending, who will receive the orders, etc.
Example: We have Work roles for Forklift operator and Warehouse operator. The truck full of parts is ready to unload. The warehouse operator would like to send the order: “Unloading the truck“ to the Forklift operator. To do so, we need to set up this Node connection between the work roles inside the Editor.