A call number is a unique identifier that is assigned to a book or other library material in order to identify its location within the library. Call numbers are used in libraries to organize and shelve materials according to a specific classification scheme, such as the Dewey Decimal Classification system or the Library of Congress Classification system.
In general, call numbers consist of a combination of letters and numbers that represent the subject or category of the material and the specific classification assigned to that material. For example, in the Dewey Decimal Classification system, the main categories are represented by the digits 0-9, and the subcategories are represented by decimal numbers. Books and other materials are assigned call numbers based on their classification, and the call numbers are used to locate the materials on the shelves.
Call numbers are an important tool for organizing and accessing library materials, and they are used in libraries around the world to help patrons find and borrow the materials they need.