Repositories are online resources that allow researchers to place their data in a secure location in order to enhance sharing and to meet mandates of granting agencies. These are also resources for locating data sets. Many repositories are discipline-specific, though some generalist repositories are also available.
Metadata Standards are specifications for the minimum information that should be collected about research data in order for it to be re-used
Metadata schemes (also called schema) are sets of metadata elements designed for a specific purpose, such as describing a particular type of information resource.