Metadata is structured information that describes, explains, locates, or otherwise makes it easier to retrieve, use, or manage an information resource. Metadata is often called data about data or information about information. It includes all cataloguing or indexing information created to locate, describe and manage the preservation of a resource. For example, metadata recorded for a digital image or photograph would include data about the content of the image, the photographer, the date of creation, date(s) of modification, technical information such as resolution, file type, file format, and its relationship with other related files and their locations.
Metadata can be grouped into general categories, including, but not limited to:
Administrative metadata provides information to help manage a resource, such as when and how it was created, file type and other technical information, and who can access it. There are several subsets of administrative data; two that sometimes are listed as separate metadata types are:
- Rights management metadata, which deals with intellectual property rights,
- Preservation metadata, which contains information needed to archive and preserve a resource.
Descriptive metadata describes a resource for purposes such as discovery and identification. It can include elements such as title, abstract, author, and keywords. For digital resources, descriptive metadata is the information used for the indexing, discovery and identification of a resource.
Structural metadata indicates how compound objects are put together, for example, how pages are ordered to form chapters. For digital resources, structural metadata is the information used to display and navigate digital resources; information on the internal organization of the digital resource; information on viewer or reader plug-in needed to open the digital resource.
Each institution will have different needs in terms of metadata and the standards and scheme they choose to use will depend heavily on the intended use.