S/4 HANA provides simplified data models and reduced tables compared to ECC. It offers three deployment options and integrates with SAP HANA cloud platform. Key changes include a universal journal to replace application index tables, Fiori UX, real-time analytics, and co-deployment of ERP modules. Data migration uses the new LTMC tool. Major finance areas like FI, CO, AA, and PCA have accounting streamlined in the universal journal with reduced transactions and simplified processes versus ECC.