Oracle OIC Integration allows you to create three types of connection which will help you to connect source and target system based on your requirement.
Trigger
Trigger is like source. If you want your connection to treat as source of your integration then select Trigger
Invoke
Invoke is like target. If you want your connection to treat as a target in your integration then select Trigger
Trigger and Invoke
Both source and target. If you want your connection to treat as a source as well as target in your integration then select Trigger and Invoke