In a general sense, all the elements of data necessary to conclusively identify a specific document, presented in some form of record.
In library cataloging, the detailed description of a copy of a specific edition of a work intended to identify and distinguish it from other works by the same author, of the same title, or on the same subject. In AACR2, the bibliographic record representing an item in the catalog includes the following standard areas of description: title and statement of responsibility (author,editor, composer, etc.), edition, material specific details, details of publication and distribution, physical description, series, notes, and standard number and terms of availability (ISBN, ISSN,price).