SAP HCI is intended as Integration Platform-as-a-Company (PAAS) which helps to integrate a number of unbiased systems/applications for a business approach. HCI can perform Cloud to Cloud, Cloud to On-premise, On-premise to On-premise and Hybrid product. HCI features Adapters (Connectivity choices) for example: Cleaning soap Adapter, IDoc, HTTP, Mail, SFTP,Ariba, https://s4-hana-cloud-faq25780.blogsidea.com/34331916/hana-cloud-integration