Library catalog

The inventory of a library's collections is referred to for users' purposes as a catalog; the librarian may use in addition a shelf list of books arranged according to catalog numbers or codes on their bindings, and an acquisition register arranged chronologically. The catalog traditionally has been a unitized life containing one or more cards per book or document according to the retrieval technique required: title, author, subject, publisher, series, language, country, etc. The advent of microforms has eventuated in replacement of card catalogs by catalog readers for microfilm and microfiche; while the advent of data processing has begun to replace these by terminals and display-units from which one can access the catalog from a number of perspectives. This in turn has influenced cataloging methods so that techniques such as title key-word entries are not cumbersome. At the same time the catalog and the circulation records can be combined and the system queried as to whether a book in the catalog is available or in use.