From Science Europe Data Glossary
Definition: data citation provides attribution to research data sources to allow for easier access to research data connected to (electronic) publications on the Internet.
Alternative definition: a data citation is a formal citation included in the reference list of published articles to data resources that led to a given research result.
Explanation: Data citations make allowances for increased acceptance and reward for research data to be considered legitimate, citable contributions to the scholarly record. Citing data also supports the reuse of data and ensures that researchers remain accountable for their data. Data citations provide an opportunity for researchers to track back to the individuals responsible for creating the data so that it can be verified and re-purposed for future study.