Library catalog – usually and historically, a master list of all the materials a library owns. Online public access catalogs (OPACs) in libraries are now often designed to provide access to all the materials a library has the right to access, whether or not the library owns that material.

Call number – the number that indicates the location of a book on the library shelves. For instance, the GMU call number for David Weinberger’s terrific book Everything is Miscellaneous is HD30.2 .W4516 2007. Books with similar call numbers have similar subjects.

Dewey Decimal Classification System – a system of classifying and organizing books by subject (and generating call numbers for them) that is usually used in public libraries.

Melvil Dewey – inventor of the Dewey Decimal Classification System, very weird and interesting guy.

Library of Congress Classification System – a system of classifying and organizing books by subject (and generating call numbers for them) usually used in research and university libraries.

Library of Congress Subject Headings – a set of official, authorized terms for describing the subject of a book — rather like “keywords” or “tags,” except very systematic and official.

Metadata (especially bibliographic metadata) – data about data. Bibliographic metadata is data about books (and similar items, such as journal articles): title, author, date, subject.

ISBN (International Standard Book Number) – a book’s ISBN is a unique number assigned to that book that helps people and machines distinguish that book from other books. Only more recent books published since 1970 will have an ISBN.

MARC (Machine Readable Cataloging). A method invented in the 1960s of encoding bibliographic metadata so that machines could read it. Library catalogs still use MARC records today.

Interlibrary loan (ILL) – a service that lets people borrow a book (or similar item) from a library other than the one they have official access to and have it delivered to their own library. Since we are part of the WRLC, the Washington Research Library Consortium, we can borrow books from most DC-area libraries.

Optical Character Recognition (OCR) – the technology that allows a scanner to recognize printed text characters on a page and convert them into digital text rather than just making an image of that page (like a photocopy).

Full text search – a search through the whole content of a digital book or article. If the full digital text is not available, either because the work has not been digitized or because the digital text has restrictions on it (if, for instance, you need to pay for it), you can usually still find the catalog or database record with bibliographic metadata that can help you decide whether you need to see the whole book.

Codex – the physical form of a printed book; cut pages bound at the back. In opposition to the scroll.

ebook – a digital book.

Digital Rights Management (DRM) – a set of technologies that controls which file formats can be accessed on which devices.

.epub – the file extension for ebooks published in the free and open EPUB format.

.mobi – the file extension for ebooks published in Amazon’s proprietary Mobipocket format.


GMU’s Library website – – a “catalog of catalogs” that includes library catalog records from thousands of libraries around the world, including of course GMU’s. There is a subscription version of WorldCat as well that is available from GMU’s list of databases under “W,” but the openly available one probably has almost everything you’ll need.

GMU’s Interlibrary Loan service –

Google Books – a collection of about 15 million scanned books from libraries that allows full-text search. Usually, however, you cannot read or download the full text of the book for free unless it is out of copyright (usually that means pre-1923 books), although there are a few more recent works that you can see the full text of. The Google Books project began in 2004 and its history is fascinating (and ongoing) — read more about it on the Wikipedia page about Google Books.

Google Books Advanced Search – a much better way to find books, especially specific books, than the default search; it will let you get more specific about what you’re looking for. – a scholarly website that in some respects is a duplicate of Google Books; it is a site where the libraries whose books Google scanned make available the scans of those books. HathiTrust is sometimes a much better place to look for books than Google Books, because trained librarians have done a lot of work to make sure the metadata is correct.

Project Gutenberg – an old (in Internet term) crowdsourced site where volunteers have put out-of-copyright books on the web. Project Gutenberg began in 1971 at one of the first computers on the ARPAnet (which of course became the Internet); as usual, please see the Wikipedia page about Project Gutenberg for its fascinating history.