catalogus

Catalogus is a Latin noun meaning a list, register, or catalogue. The word derives from Greek katalogos, “a reckoning or listing,” through Latin into the modern Romance and Germanic languages. In English, the form catalogue comes via French from Latin, while catalog is a shortened form that also arose in English. In Dutch, catalogus is used with the same sense as the English catalogue or catalog.

In classical and medieval contexts, catalogus designated a formal enumeration of items, such as books, manuscripts, ships, or officials. Scholarly and ecclesiastical writers used catalogs to organize knowledge and holdings. The term also appears as a title element in inventories and bibliographic lists, indicating a complete or curated register.

Today, catalog (or catalogue) refers to an organized listing within a system. In libraries and archives, the library catalog is a searchable database of holdings and their locations. In museums, catalogues describe objects in collections; in commerce, product catalogs present items for sale. Digital catalogs rely on metadata and controlled vocabularies, and use standards such as MARC, Dublin Core, and thesauri to enable consistent search and retrieval.

The Latin form catalogus remains a common scholarly term in Latin titles and bibliographies to denote a complete listing. The broader concept—cataloging—is to systematically describe, index, and locate items, a practice central to libraries, museums, and digital repositories.