What do you mean by system of record term?

System of Record (SOR) is an information storage and management system that protects data integrity, and serves as the authoritative source for specific data items in systems where multiple sources of the same items exist. A system of record (SOR) or source system of record (SSoR) is a data management term for an information storage system (commonly implemented on a computer system running a database management system) that is the authoritative data source for a given data element or piece of information.