Digital libraries as occasioned by the information and communication technology (ICT) revolution has given Nigeria a chance to stamp and showcase her authority in knowledge and subsequently contribute as never before in the national development through university education. Hence, university education in Nigeria began with the establishment of the University College Ibadan in 1948 during British Colonia masters. Immediately after the Nigerian Independence celebration in 1960, four additional universities were established. Thus: University of Lagos, University of Nigeria, Nsukka, Obafemi Awolowo University, Ile-Ife and Ahmadu Bello University, Zaria. These were referred to as the first generation universities in Nigeria with the aimed to lead in man-power development and advancement in educational development of the country. However, in the 1970s, seven more additional universities were founded, and they were referred to, as the second generation universities, which among them were: Usmanu Danfio University Sokoto and Bayero University, Kano. these were found in the North West Zone. These universities greatly help bringing university education closer to the citizens of the country, Ogunsola (2005).The third generation universities came on board in the 1980s with the establishment of Federal University of Technologies and Agricultures. None was established in the northwest zone.
For the purpose of the high quest for education and also the need to increase man power development in Nigeria state own universities began to spring up by individual states in Nigeria. In line with this, all states in the Northwest zone of Nigeria (seven states) established their own state universities which marked the fourth generation Universities. In 1990s the law for the establishment of private universities was legalized and led to the establishment of private universities across the nation which the zone was not an exception. Today, there are over one hundred accreditated public and private universities in Nigeria. On record, sixteen of them are from the Northwest zone of the country. All aim at working towards the educational advancement and human resources development of the nation, (NUC, 2014).
Generally, the university library objective is to support academic activities in their university community. To achieve this, relevant resources of all kind need to be put in place to satisfy the learning, teaching and research needs of users. According to Ani and Edem (2012), the resources utilized in the university libraries were mostly in printed format made up of books, journals, magazines, dissertations/theses and other local materials.
However, in the recent development, libraries experience new technological transformation identified as the electronic information era been powered by Information and Communication Technologies (I.C.T.) with its capabilities in promoting and improving information services in all facer of live led to the establishment of digital libraries in Nigerian universities. In line with this development, all universities in the Northwest zone also adopted the trend of setting up the digital libraries. From the foregoing, this paper seeks to explore the emergence of the digital libraries in Nigerian Universities in Northwest Zone and also identify challenges and prospect of digital libraries using documentary and secondary data.
REVIEW OF RELATED LITERATURE
There is no single definition for digital libraries. The definition evolves as research progresses. Within the context of libraries, digital libraries may be viewed as technical services performed electronically with an entirely electronic application. The e-libraries are "a set of electronic resources and associated technical capabilities" and that are designed to serve specific users community, (Buckland's electronic library, 2012). Trivedi (2010) defined digital library as "a library in which collections resources are stored in digital formats (as opposed to print, microform, or other media) and accessible by computers." Aman and Norliyanan (2002) stated that an electronic library also refer to as digital library or digital repository focused on collection of digital objects that can include text, visual material, audio material, video material, stored as electronic media formats (as opposed to print, micro form, or other media), along with means for organizing, storing, and retrieving the files and media contained in the library collection," They also viewed it as "a potentially virtual organization, that comprehensively collects, manages and preserves for the long dept of time rich digital content, and offers to its targeted user communities specialized functionality on that comprehensive codified policies."
Universally, Digital libraries are perceived as libraries in which all information resources are available in computer process through which acquisition, storage, preservation, retrieval and dissemination of resources are carried out using digital technologies. Mutula and Ojedokun (2008) noted that it is a library that contains no conventional print information resources, but electronic books, journals and newspapers. They further observed that the digital library may not occupy a physical space, where as users need to go and gain access to its electronic resources.
In another development, Li and Furht (2014) stated that digital libraries are systems that combine the machinery of digital computing storage and communication, in which the content, and software needed to reproduce, emulate and extend that services of collecting, cataloguing, finding and disseminating information offered by traditional libraries based on paper and other materials. "They also viewed digital libraries as systems providing a community of users with coherent access to a large, organized repository of information and knowledge." The ability of the user to access, reorganize, and utilize this repository is enriched by the capability of digital technologies.
The digital library is synonymous to the virtual library which is a library where services or collections of electronic resources are entirely virtual and access via a network. A virtual library does not have a physical space where users can visit to access information resources, instead distribution of resources are done electronically virtually. It is also called a paperless library. Digital libraries and virtual library are characterized by the following features as noted by (Costabile and Semeraro, (1998) access to information over a network, facilitate immediate and simultaneous access to information, they are interactive, i.e. support 2 ways communication with the users, they exist in multimedia format of text, video, graphics, sound and animation. Above all, it increases speed and effectiveness in finding information and to decrease mental effort put into each search of information in the net.
The e-library (EL) most often referred to as digital library; virtual library and online library are not one and the same. According to Irokwe (2001), a digital library is a library that harnesses digital technologies as infrastructure to search, collect, organize, store and distribute cultural, historical and scientific information whether it is text, visual images or sound. This requires that all operations of the library are computerized. Such operations include selection and acquisition, cataloguing and classification etc. It comes into existence due to inconveniences of traditional library system. The digital library contains resources that are either born digital or digitized resources that pass through the process of transformation from hard to soft copies. It also developed electronic catalogue of all library materials, networking this catalogue, so that users not only in the library but also from elsewhere can access it. Additionally, digital library includes the digitalization of locally produced information and the establishment of institutional repositories, to provide access to the scholarly material produced by members of the university.
According to Daniel (2002), Nancy Schiller was one of the first writers to use the expression "virtual". Schiller simply uses the term as "libraries in which...