- A digital library is the most current and widely accepted term to designate an organized collection of open access digital documents constructed to serve a community of users. It can be called as well virtual library or electronic library. Digital libraries pursue the same purpose, functions ans goals as traditional libraries, with a focus on digital formats.
- “The term "digital libraries" covers the creation and distribution of all types of information over networks, ranging from converted historical materials to kinds of information that have no analogues in the physical world.” (Arms, 1999)
- “The term "digital library" escapes precise definition, often being used interchangably with "virtual library," or "electronic library".” (Cleveland Digital Library, retrieved 12:20, 25 October 2006 (MEST)).
Some definition focus on digitalization of traditional libraries
- “A digital library is a library in which a significant proportion of the resources are available in machine-readable format (as opposed to print or microform), accessible by means of computers. The digital content may be locally held or accessed remotely via computer networks. In libraries, the process of digitization began with the catalog, moved to periodical indexes and abstracting services, then to periodicals and large reference works, and finally to book publishing.” (Wikipedia, retrieved 12:20, 25 October 2006 (MEST))
Some definitions include some added value:
- “A digital library is much more than just the collection of material in its repositories. It provides a variety of services to all of its users (both humans and machines, and producers, managers, and consumers of information).” 
- Learning object repository and the list of Learning objects repositories
- Services that can be combined with a digital library, e.g. citation indexes and reference managers. Such services usually include social computing features like sharing and social navigation
2 Types of digital libraries
Note: It is not very clear to DSchneider how and whether we should distinguish libraries from more sophisticated archives.
- On-line catalogs of printed materials
- On-line books and journals
- Somewhat digital libraries
- Publications of academic units (indexed archives of papers and other digital artifacts)
- Learning objects repositories
- open educational resources web sites
- Digital services that provide similar functionality
- On-line citation indexes and reference manager that provide transparent access to publications
- Publishing companies (in particular ones that sell electronic journals)
- Booksellers like Amazon ?
- Search engines like Scholar.google.org ?
- D-Lib Magazine, is a solely electronic publication with a primary focus on digital library research and development, including but not limited to new technologies, applications, and contextual social and economic issues. (Open access)
- Arms William Y. (1999), Digital Libraries, MIT Press, ISBN 0-262-01180-8.
- Leiner Barry M. (1998). The Scope of the Digital Library, Draft Prepared for the DLib Working Group on Digital Library Metrics HTML, retrieved 12:20, 25 October 2006 (MEST).