SAP HCI is built as Integration Platform-as-a-Support (PAAS) which really helps to combine a number of unbiased units/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, https://s4-hana-cloud-architectur26925.blogsumer.com/27940624/hana-cloud-integration