Secondary use of data occurs when data is extracted from its primary context of origin, combined with other data and used for further, secondary purposes.

The great economic value of data lies in such secondary uses, as demonstrated by platforms such as Google, Facebook and Amazon, whose business models are essentially based on the accumulation and reuse of data. However, the secondary use of data also plays a decisive role in practically all scientific fields in order to verify research results or gain new scientific insights.

The term "secondary use of data" should be distinguished from the broader term "data management". Data management encompasses all technical, organizational and legal aspects in the life cycle of data - from the collection, management and storage of data to archiving or destruction. The preparation and publication of data for secondary use is a sub-aspect of the data life cycle.