This paper discusses the definitions of a digital library from four
different points of departure. The digital library is a term now widely accepted
as a description of the use of digital technologies by libraries to acquire,
store, conserve and provide access to information. The impacts of digital
library technologies and concepts on traditional libraries in such aspects as
collection development, technical services and reader services, and on the roles
that librarians play in the society, are studied. This paper also studies some
important issues concerning the development of digital libraries, including
technical issue, copyright issue, economic pressure, standards issue and the
issue in the preservation of digital information.