What is a Data Deduplication?

In a CRM this usually means two contact records for the same person created from different signup sources; in storage systems it means literally storing repeated byte sequences only once and referencing them elsewhere to save space. Both share the same core challenge: deciding what counts as "the same" when records aren't byte-identical - fuzzy matching on name, email, and phone with tolerance for typos and formatting differences is where most of the engineering effort goes. The merge step is often harder than the detection step. Once two records are flagged as duplicates, something has to decide which values win when they conflict - the most recent update, the most complete record, or a manually reviewed decision for high-value records - and that merge needs to preserve an audit trail in case it was wrong. Left unaddressed, duplicate records quietly corrupt everything downstream: email campaigns double-send, revenue reports overcount, and support agents can't tell which record is authoritative.