The document discusses the key components and functions of an integrated library system (ILS). An ILS is an automated software system that integrates the main library management functions, including acquisition, cataloguing, circulation, and serials control. It comprises a relational database and separate software modules for each function. Larger libraries use ILSs for acquiring, receiving, cataloguing, circulating, and tracking library materials. Common ILS modules discussed are administration, acquisition, circulation, cataloguing, and interlibrary loan.