SAP HCI is built as Integration System-as-a-Assistance (PAAS) which really helps to combine many unbiased devices/apps for a business approach. HCI can do Cloud to Cloud, Cloud to On-premise, On-premise to On-premise and Hybrid model. HCI offers Adapters (Connectivity options) such as: Cleaning soap Adapter, IDoc, HTTP, Mail, SFTP,Ariba, oData. https://s4hanacloudonboarding70257.blogmazing.com/27841084/hana-cloud-integration