In this article, different definitions of the term Digital Libraries are discussed. Two major definitions are dwelled upon: one emerging from the library world and the other from the world of scientific research. Librarians tend to speak for a broader definition of the term “Library”. They see a library as an organisation that secures the selection, conservation, organisation, preservation and the access to information that is vital for the members of the specific organisation. Researchers most often favour a narrower definition of the library concept. For them a library could be any room containing a smaller or bigger amount of books or data discs or tape cassettes. Researchers seldom care for the social and institutional context of the term “Library”. Their emphasis is tilted towards databases and how to collect, retrieve, organise and access the information. Future use, development and problems of Digital Libraries, their content, users and their staffing are discussed. For example, the technical issues which include the problem with standards and protocols. To bring the distributed variety of digital resources and services together in a way that allow for integration and unified search, retrieval and presentation is a great challenge for the future. So is the problem of transferring personalised service and support from standard library and information services to the digital library. A user interface can hardly replace person to person service but better user interfaces must be developed and researched in order to help users.