libraryinformation

Library information refers to the information resources held by libraries and the metadata, systems, and services that enable discovery, access, and use of those resources. It encompasses both the actual content—such as books, journals, audiovisual materials, and digital objects—and the information about those items, including bibliographic records, metadata, and authority data. The field that studies, designs, and manages these aspects is library information science.

Core activities include cataloging, classification, and metadata creation according to standards such as MARC, Dublin Core, and Resource Description and Access (RDA). Authority control and subject headings (for example Library of Congress Subject Headings) help ensure consistent indexing and retrieval. Library information is organized in catalogs and discovery layers, and accessed through integrated library systems, library management systems, or online public access catalogs.

Information systems also manage digital assets in repositories and provide discovery, search, link resolution, and persistent identifiers. Interoperability standards and protocols (Z39.50, SRU/SRW, APIs) enable data exchange between libraries and external services. Linked data initiatives, including BIBFRAME, are expanding the use of semantic relationships in bibliographic data.

Library information services include reference and information literacy instruction, research assistance, and user education. Access to resources is governed by licensing, copyright, and privacy considerations, with libraries balancing open access goals and patron rights.

In modern practice, user-centered design, data quality, and privacy protection are emphasized, while libraries also explore analytics and open data to improve discovery and resource planning.