Cataloging is the process of creating and systematically arranging records which describe materials held by a particular repository. These records are designed to facilitate search and retrieval, and support administrative activities such as acquisitions, circulation, preservation, and rights management.
A record generally consists of a description, and often includes headings (for topics, persons, places, etc.); a classification (or call) number (based on an established classification scheme which arranges classes, usually subject classes, according to a set of pre-established principles); and links to related descriptions, Web sites, or records documenting correct form and use of headings (authority records). A catalog is often distinguished from a simple listing or database of descriptions by the imposition of a controlled vocabulary (an established list of preferred terms, with cross references), and by mechanisms which allow users to draw relationships between various entities. Some archives create collection-level records, wherein a single record collectively describes a group of individual items. In some cases these collection-level records are supplemented by finding aids (paper or computerized listings of the individual items). Catalog records may be found on a stand-alone computer, on a networked computer, on the Web, in a card or book catalog, or on microform.
Rules which govern the content of the descriptions are content standards; these are the guidelines which prescribe what type of information is recorded (title, credits, notes, etc.) and how it is formatted (for example, initial articles should be dropped from titles, or names should be formatted as Lastname, Firstname). The resulting catalog description is also known as metadata, or data about data. A metadata schema is a standardized structure for metadata which allows repositories or machines to share data with mutual understanding. The metadata schema defines the data elements (fields) or tags (labels) used to enable indexing, retrieval, display, and sharing of records by computer systems.
Cataloging is guided by a series of principles, and the catalog records or metadata reside in a cataloging system,sometimes called an integrated library system or digital or media asset management system. Institutions may also contribute their records to a bibliographic utility, an organization that provides access to and support for databases and information retrieval systems, either directly to member libraries or through a network of regional service centers, usually via a proprietary interface. The largest bibliographic utilities in the U.S. are RLIN and OCLC.