1. Oracle Cloud Infrastructure Documentation. Using Integrations in Oracle Integration 3
"About Connections".
Reference: The documentation states
"Connections define information about the instances of each configuration you are integrating... A connection is a resource that you create for each application instance that you want to integrate." This directly supports that connections specify the source and target applications.
2. Oracle Cloud Infrastructure Documentation. Get Started with Oracle Integration 3
"Oracle Integration Components"
Section: "Connections".
Reference: This guide explains
"Connections are the resources that you configure to connect to the specific instances of the applications that you want to integrate... For example
to integrate an Oracle Service Cloud (RightNow) application and a Salesforce application
you create an Oracle Service Cloud (RightNow) connection and a Salesforce connection." This confirms connections are for defining the applications being integrated.