Over recent years, libraries have grown increasingly reliant on digital materials. Libraries are encountering for new resources, which are "Born digital" and have no print or analogue equivalent - they exist only in digital form. The introduction of digital technologies into the processes of production, distribution & storage of information challenges the capacity and ability of libraries & other cultural institutions to carry out their responsibility for preservation. As universities, regional research centers, laboratories, corporations, and professional societies develop their own depositories of information and make them available to the world's networks, they take on the publisher's and the library's traditional roles. Digital surrogates can assist in deflecting demand away from handling Originals (provided highquality images are readily available), not only for detailed analysis of the items but also for browsing.