SAP HCI is built as Integration System-as-a-Assistance (PAAS) which helps to combine a number of impartial methods/purposes for a business approach. HCI can perform Cloud to Cloud, Cloud to On-premise, On-premise to On-premise and Hybrid design. HCI offers Adapters (Connectivity alternatives) for example: SOAP Adapter, IDoc, HTTP, Mail, SFTP,Ariba, oData. https://s4-hana-cloud-trial26036.boyblogguide.com/27703178/hana-cloud-integration