NSF or Notes Storage Facility is a database supported by both IBM Lotus Notes and IBM Domino server. NSF file stores data in document unit which is termed as Notes. It comprises of crucial information of a Notes account like emails, contacts, user data, design information, appointments and so on.
NSF files are generally hosted by the IBM Domino server, and can be effortlessly downloaded by the Notes clients for using the fully functional database in offline mode. If Notes user modify, edit, or perform any reflecting changes in database then it is automatically synchronized by Domino server in the master database.