Moving data from one system, format, or storage location to another.
Data migration happens when an organization upgrades software, consolidates systems, moves to the cloud, or changes how data is stored. It involves extracting data from the source, transforming it to fit the target system, and loading it — essentially a one-time or phased ETL process.
Migrations carry risk: data can be lost, corrupted, or mismatched if not carefully planned and validated. A migration plan typically includes a full inventory of source data, mapping rules, test runs, and rollback procedures.
Example: A municipality migrates its property assessment records from a legacy mainframe system to a modern relational database. Each field must be mapped, date formats converted, and duplicate records resolved before the new system goes live.