A library is a collection of sources, resources, and services, and the structure in which it is housed: it is organized for use and maintained by a public body, an institution, or a private individual. In the more traditional sense, a library is a collection of books. The term can mean the collection, the building that houses such a collection, or both.
Public and institutional collections and services may be intended for use by people who choose not to — or cannot afford to — purchase an extensive collection themselves, who need material no individual can reasonably be expected to have, or who require professional assistance with their research. However, with the sets and collection of media and of media other than books for storing information, many libraries are now also repositories and access points for maps, prints, or other documents and various storage media such as microform (microfilm/microfiche), audio tapes, CDs, cassettes, videotapes, and DVDs. Libraries may also provide public facilities to access subscription databases and the Internet.
Thus, modern libraries are increasingly being redefined as places to get unrestricted access to information in many formats and from many sources. In addition to providing materials, they also provide the services of specialists, librarians, who are experts at finding and organizing information and at interpreting information needs. More recently, libraries are understood as extending beyond the physical walls of a building, by including material accessible by electronic means, and by providing the assistance of librarians in navigating and analyzing tremendous amounts of knowledge with a variety of digital tools.
The term "library" has itself acquired a secondary meaning: "a collection of useful material for common use," and in this sense is used in fields such as computer science, mathematics and statistics, electronics and biology.
Directories of libraries
- American Library Association's list of largest US libraries
- lib-web-cats: A directory of over 39,000 worldwide libraries spanning 139 countries maintained by Marshall Breeding
- LibLinks - Directory of library resource links organized by US states
- LibWeb - Directory of library servers via WWW
- Libraries of the World and their Catalogues compiled by a retired librarian
- National libraries of Europe
- UNESCO Libraries Portal - Over 14000 links worldwide
- Centre for the History of the Book
- Wikisource, The Free Library
- Libraries: Frequently Asked Questions
- International Federation of Library Associations and Institutions
- Professional Library Associations from Jenkins Law Library
- A Library Primer, by John Cotton Dana, 1903, setting out the basics of organizing and running a library
- Memory’s Library explores the origins of the modern library
- A Compendium of Beautiful Libraries