A library catalog is a register of all bibliographic items found in a library or group of libraries, such as a network of libraries at several locations. A catalog for a group of libraries is also called a union catalog. A bibliographic item can be any information entity that is considered library material, or a group of library materials, or linked from the catalog as far as it is relevant to the catalog and to the users (patrons) of the library.

Bibliography, as a discipline, is traditionally the academic study of books as physical, cultural objects; in this sense, it is also known as bibliology. English author and bibliographer John Carter describes bibliography as a word having two senses: one, a list of books for further study or of works consulted by an author ; the other one, applicable for collectors, is "the study of books as physical objects" and "the systematic description of books as objects".