Use a Custom Template in case you want a customized Process Flow for your complex Transactions. The Custom Template provides you with the flexibility to use the following activities suiting your requirements:
Multiple Source and Target activities with corresponding Source and Target schema
Inbound Template helps in receiving data from the Partner. In this Template, your Partner defines the Source application with configuration details and the Company defines the configuration for the destination.
Outbound Template helps in sending data to the Partner. In this Template, Company defines the Source application with configuration details and your Partner defines the configuration for the destination.