Making API calls to other applications

Hi There,

At a high level, I'm trying to understand how Adobe Campaign Classic (v6.1.1) can connect (transfer data) to other applications over API.

I have a little experience of understanding the SOAP methods and how external applications can make SOAP calls to Adobe Campaign to perform actions, but I'm wondering what's possible the other way, and what are common uses to connect Adobe Campaign with other API endpoints.

Is there any high level use cases or documentation?

I'm thinking the most common use case would be a client/3rd party needing a regular transfer of data from various schemas.

If their application is the API end point. How could the data transfer be achieved? (Is it something that can be configured within the console, perhaps a query activity to retrieve the data and then another activity to configure the transfer over API?) And are both SOAP and REST available in such a scenario.

I've done a lot of batch SFTP data exports over the years, just looking to understand what's possible over API as I think this could be a more elegant way to exchange data between Adobe Campaign and external applications.

Thanks

David