Identity Correlation
Linking a known identity to its accounts across every application it touches — and, in the opposite direction, reconciliation, scanning existing accounts to flag ones matching no known identity.
aka: reconciliation
Correlation and reconciliation are two directions of the same problem. Correlation starts from the identity and finds its accounts; reconciliation starts from the accounts and asks whether an identity still exists behind each one, usually assigning a confidence score rather than a hard yes/no match.