A library can be understood as a system because it consists of various interrelated components that work together to achieve common objectives. In the context of the management of library and information centres, the systems approach helps library managers understand the library as an organized and dynamic unit rather than merely as a collection of books. The primary purpose of a library system is to acquire, organize, preserve, retrieve and disseminate information to meet the changing needs of its users. A system generally consists of inputs, processes, outputs and feedback. A library also follows this pattern. The major inputs of a library include information resources, financial resources, human resources, infrastructure, technology and information about users. Books, journals, databases, electronic resources, reports, manuscripts and other information materials constitute important resource inputs. Funds provided by the parent institution or government enable the library to acquire resources and maintain its services. Librarians and other employees constitute the human input necessary for performing different activities. The processing component transforms these inputs into useful library services. Selection and acquisition of documents, classification, cataloguing, indexing, abstracting, shelving, preservation and digitization are important processing activities. Modern libraries also process electronic resources through