Cataloging and Classification/What is descriptive cataloging?

Descriptive cataloging is the process of identifying and describing the bibliographic and physical form of an item, determining the name(s) and title(s) that will be used as access points, and recording these data in a bibliographic record. In the United States, AACR2 and RDA are the codes used for descriptive cataloging.

Other forms of description
Catalogers do more than transcribe what they see. Catalogers may supplement a descriptive record with additional access points, may correct any publishers' errors,

Descriptive cataloging vs. subject cataloging
Descriptive cataloging describes what an object is, rather than what it is about. While the title proper of a book may hold clues about a book's contents, it may also be vague, intentionally misleading, or in a language unknown to many users of the catalog. A purely descriptive catalog record is often enhanced by adding subject headings, which convey what the book is actually about, before it is added to a library's catalog.