Define bibliographic classification?

Bibliographic classification is a system for organizing and classifying library materials based on their subject matter or content. The purpose of bibliographic classification is to make it easier for patrons to find materials on specific subjects in a library. There are many different bibliographic classification systems in use around the world, including the Library of Congress Classification (LCC) system, the Dewey Decimal Classification (DDC) system, and the Universal Decimal Classification (UDC) system. Bibliographic classification systems generally use a combination of letters and numbers to represent different subjects and subtopics, and may also include indexes and other tools to help patrons locate materials on specific subjects. Bibliographic classification systems are used in libraries of all sizes, from small public libraries to large research libraries.