How to use the Signal action in a Process Flow?

Question:

I am trying to spawn four separate process flows in a single flow. I have used the Spawn activity four times,

but it is asking for a Signal:

Signal: Name for the signal that is generated after the asynchronous process flow (sub-flow) is completed. This property is applicable only when Wait for Child property is set to true.

The definition is not clear as to what this should be?

Answer:

The signal is used by the parent flow to determine if the child flow has completed executing or not. You should be able to set the value of the signal to any string value. The signal is used in case when "Wait for Child" property is set to True in that case the parent flow waits for the child flow if it is completed it's execution(Failed/Executed). If a signal with same name returns then it proceeds further and it has nothing to do with the value of signal as it simply works as relay.