Recording is the assignment of sequential "instrument" numbers to documents, as they are presented. Many different document types are recorded concerning real property mortgages, deeds, satisfactions, assignments, leases, etc., as well as documents from court cases and other sources. The recorded documents create the Official Records.
Official Records are comprised of all recorded documents. These include real estate documents and particular court documents if they are required to be recorded in the Official Records. They are public records, but not all public records are Official Records. Official Records are available online from 1921 to the present.