Metadata

An item of metadata may describe an individual datum (content item) or a collection of data (content items). Metadata is used to facilitate the understanding, use and management of data. The metadata required for this will vary with the type of data and context of use. So, in the context of a library, where the data is the content of the titles stocked, metadata about a title might typically include a description of the content, the author, the publication date and the physical location. In the context of a camera, where the data is the photographic image, metadata might typically include the date the photograph was taken and details of the camera settings. In the context of an information system, where the data is the content of the computer files, metadata about an individual data item might typically include the name of the field and its length. Metadata about a collection of data items, a computer file, might typically include the name of the file, the type of file and the name of the data administrator.