Deduplication
Deduplication is entity matching applied within a single dataset, finding and resolving records that refer to the same entity so each real-world thing appears once.
Deduplication is the special case of entity matching where you match a dataset against itself. The goal is a clean set of records where each customer or product appears exactly once, with duplicates linked or merged.
It uses the same machinery as cross-dataset matching, blocking to generate candidate pairs within the table and then matching to classify them. It faces the same scaling problem, since the number of within-table pairs grows quadratically with the number of rows.