A connection is an instance of an adapter, configured to use a particular endpoint and credentials.
Oracle Integration Cloud Service includes a set of predefined adapters, which are the types of applications on which you can base your connections, such as Oracle Sales Cloud, E-business suite, SOAP, REST, and others.
A connection is based on an adapter. A connection includes the additional information required by the adapter to communicate with a specific instance of an application (this can be referred to as metadata or as connection details).
For example, to create a connection to a Salesforce cloud application instance, you must select the Salesforce adapter and then specify the Enterprise WSDL URL, security policy, and security credentials to connect to it.
Types of Connection
ICS allows you to create three types of connection based on your requirement.
1) Trigger: Trigger is like source. If you want your connection to treat as source of your integration then select Trigger
2) Invoke: Invoke is like target. If you want your connection to treat as a target in your integration then select Trigger
3) 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