Metadata: 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. Metadata shares many similar characteristics to the cataloguing that takes place in libraries, museums and archives.
a) Metadata Schema: There are literally hundreds of metadata schemas to choose from and the number is growing rapidly, as different communities seek to meet the specific needs of their members. Each metadata schema usually has three main characteristics- A limited number of elements, the name of each element, and the meaning of each element. Two commonly used metadata schema are Dublin Core (http://purl.oclc.org/metadata/dublin_core/), and Anglo-American Cataloging Rules (AACR-II).
i) Dublin Core: The Dublin Core Metadata Element Set arose from discussions at a 1995 workshop sponsored by OCLC and the National Center for Supercomputing Applications (NCSA). As the workshop was held in Dublin, Ohio, the element set was named the Dublin Core. The continuing development of the Dublin Core and related specifications is managed by the Dublin Core Metadata Initiative (DCMI). The fifteen-element of Dublin core are Title, Creator, Subject, Description, Publisher, Contributor, Date, Type, Format, Identifier, Source, Language, Relation, Coverage, and Rights. The fifteen-element "Dublin Core" achieved wide dissemination as part of the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) and has been ratified as IETF RFC 5013, ANSI/NISO Standard Z39.85-2007, and ISO Standard 15836:2009.
b) Creation of Metadata: The metadata can be created and collected at point of creation of a resource or at point of publication. There are many such tools available and the number continues to grow. Such tools can be standalone or part of a package of software, usually with a backend database or repository to store and retrieve the metadata records, some examples include:
i) DC-dot (http://www.ukoln.ac.uk/metadata/dcdot/). This service will retrieve a Web page and automatically generate Dublin Core metadata, either as HTML tags or as RDF/XML, suitable for embedding in the section of the page.
ii) DCmeta (http://www.dstc.edu.au/RDU/MetaWeb/generic_tool.html). Developed by Tasmania Online. It is based on SuperNoteTab text-editor and can be customized.
iii) HotMeta (http://www.dstc.edu.au/Research/Projects/hotmeta/). A package of software, including metadata editor, repository and search engine.