A data library is a collection of numeric and/or geospatial data sets for secondary use in research. (Scroll down to view definition from the Online Dictionary for Library and Information Science.) A data library is normally part of a larger institution (academic, corporate, scientific, medical, governmental, etc.) established to serve the data users of that organisation. The data library tends to house local data collections and provides access to them through various means (CD-/DVD-ROMs or central server for download). A data library may also maintain subscriptions to licensed data resources for its users to access. Whether a data library is also considered a data archive may depend on the extent of unique holdings in the collection, whether long-term preservation services are offered, and whether it serves a broader community (as national data archives do).