SAP S/4HANA is SAP's next generation ERP system that runs on the SAP HANA in-memory database for faster analytics and reporting. It allows companies to convert their existing SAP ECC systems to SAP S/4HANA. The document discusses what SAP S/4HANA and SAP HANA are, the different types of SAP S/4HANA and ECC projects, and how the SAP Readiness Check tool can help companies assess their ECC system's readiness for conversion to S/4HANA. It also provides some links for additional information on SAP S/4HANA implementation and features.