Metadata is data that provides information about other data, generally a dataset.
These data, in combination with documentation, help you, your colleagues, and computers to comprehend the meaning behind the data in the datasets.
Metadata also enables interoperability (i.e., the ability to exchange data and interpret that data) since it provides a clear definition of the data that can be used to interpret it. Most metadata in medical datasets is added using ontologies.
For more information, see our blog article: Metadata: What are they and why do I need them?