Difference between CI-6 (CLOUD INTEGRATION) x WEBSERVICE

Hi Ariba Experts

Someone could you please explain for the integration matters whats the difference between CI -6 X Webservice, or if they are exactly  the same thing ?

For my point of view it works like that :

CI-6  Chain

SAP ECC --> SAP PI --> ARIBA ADAPTER (INSIDE OF SAP PI)   --> ARIBA NETWORK --> ARIBA SOURCING --> ARIBA NETWORK ->  ARIBA ADAPTER (INSIDE OF SAP PI)

WEBSERVICE  Chain

SAP ECC ---> EXPORT MASTER DATA IN A CSV FILE --->  ARIBA NETWORK --->  ARIBA SOURCING --> EXPORT THE CSV FILE ---> ARIBA NETWORK --->  SAP ECC

Could some one review the both flow above  and described if they are correct ?

Regards

Marcel H.