Glossary
Data Lineage
Data lineage tracks where a piece of data originated and what transformations it passed through to reach its current form — which source fields fed a report, which raw records a summary was computed from. Without this record, a derived artifact's actual sensitivity is essentially a guess: nothing ties it back to the original data whose classification it should arguably inherit, in whole or in part.
Lineage becomes an access-control question the moment a transformation changes who should be allowed to see the result. A report aggregated from sensitive source records might be safe to share broadly; a report that merely reformats sensitive records without aggregating anything usually isn't — and telling the two apart depends on actually knowing the lineage, not on the report's shape alone.