Library is a place where the collection of information resources in print or in other forms that is organized and made accessible for reading or study is kept. International Organization for Standardization has defined library as irrespective of the title, any organized collection of printed books and periodicals or of any other graphic or audio-visual materials, and the services of a staff to provide and facilitate the use of such materials as are required to meet the informational, research, educational or recreational needs of its users.
Advances in Information Communication Technology (ICT), particularly the World Wide Web (WWW) have seen the evolution of the automated library, electronic library, digital library, virtual library, Hybrid library etc.
A. Traditional Library: Traditionally, libraries were collections of books, manuscripts, journals, and other sources of recorded information. The collection of the traditional libraries are mostly print media, manuscripts etc. and are not well organized. The documents are deteriorating at a rapid rate, the collected information is not easy to locate and procure. Such information does not reach the user of the libraries on time. It is difficult to get such publications in the absence of personal influence and contacts. There are certain restricted publications containing highly informative materials but may not be easily available. Sometimes the information is published after many years. By the time it is published, the information becomes obsolete and then abandoned. Since it is not properly indexed or listed, the researcher is forced to go through long and tedious process to ascertain whether any material of his/her interest is available or not. Here the collections are not well organized and some reports are deteriorating at a rapid rate. Preserving them in their original form is difficult and it is not cost effective. Again the traditional libraries are confined itself within a physical boundary.
B. Automated Library: A library with machine-readable catalog, computerized acquisition, circulation and OPAC are called as automated library. The holdings of such types of libraries are same as that of traditional libraries.
C. Electronic Library: When automated libraries go for LAN (Local Area Networking) and CD-ROM networking and started procuring E-journals and other similar kinds of publications then it is known as electronic library. The resources of the electronic libraries are in both print and electronic form. The electronic media are used for storage, retrieval and delivery of information.
D. Digital Library: It is a later stage of electronic library. In digital library high speed optical fiber are used for LAN and the access is over WAN and provide a wide range of Internet based services i.e. audio and video conferencing and like other. The majority of the holding of a digital library is in the computer readable form and also acts as a point of access to other online sources.
E. Virtual Library: It is a companion term to digital library, brought forth by the National Science Foundation. The concept of virtual library also emerged simultaneously with electronic library and digital library. This emergence is perhaps because all the information uses are at present through networked libraries at the desktop which is quite virtual (practical) without the physical existence of books on shelves. A virtual library can be simply defined as the internet-based digital library or a library without walls. The concept of virtual library is that any person who has a computer and connection to the library networks can access not only the resources of that library but also a variety of information available through national and international networks like internet and intranet without being physically present in the library.
F. Hybrid Library: It was designed to bring a range of technologies from different sources together in the context of a working library and to explore integrated systems and services in electronic and printed environments. It reflects the transitional state of the library, which today can neither be fully printed nor fully digital.