SAP HANA (High-Speed Analytical Appliance) is an in-memory database
platform developed by SAP SE which will be deployed on-premises or
within the cloud. It uses in-memory computing to store compressed
data in random access memory (RAM), instead of storing it in relational
databases on disk drives.
SAP ECC is that the ERP system and SAP HANA is that the in-memory database
designed to handle transactions and analytics. HANA was originally designed
to be a knowledge warehouse, but it's grown into an all-in-one data platform
that manages analytical, transactional, and application development.