ECM
Software that manages unstructured information such as e-documents, document images, email, word processing documents, spreadsheets, web content, and other documents; most systems also include some records management capability.
EFSS
Enterprise File Synchronization and Sharing
Enterprise file sync-and-share is a service that allows users to save files in cloud or on-premises storage and then access them on desktop and mobile devices. This is a service that offers large businesses and enterprises a secure way to transfer files both internally and externally (e.g. with partners and customers).