Definitions :

• "The generic name for federated structures that provide humans both intellectual and physical access to the huge and growing worldwide networks of information encoded in multimedia digital formats."

(The University of Michigan Digital Library: This Is Not Your Father's Library,  Birmingham, 1994)
• "Systems providing a community of users with coherent access to a large, organized repository of information and knowledge." 
  (Lynch, 1995)
• "Digital libraries are a set of electronic resources and associated technical capabilities for creating, searching, and using information. In this sense they are an extension and enhancement of information storage and retrieval systems that manipulate digital data in any medium (text, images, sounds; static or dynamic images) and exist in distributed networks. The content of digital libraries includes data, metadata that describe various aspects of the data (e.g., representation, creator, owner, reproduction rights), and metadata that consist of links or relationships to other data or metadata, whether internal or external to the digital library. 
  (UCLA-NSF Social Aspects of Digital Libraries Workshop)
• Digital libraries are constructed -- collected and organized -- by a community of users, and their functional capabilities support the information needs and uses of that community. They are a component of communities in which individuals and groups interact with each other, using data, information, and knowledge resources and systems.In this sense they are an extension, enhancement, and integration of a variety of information institutions as physical places where resources are selected, collected, organized, preserved, and accessed in support of a user community. These information institutions include, among others, libraries, museums, archives, and schools, but digital libraries also extend and serve other community settings, including classrooms, offices, laboratories, homes, and public spaces."
(UCLA-NSF Social Aspects of Digital Libraries Workshop)
• "systems providing a community of users with coherent access to a large, organized repository of information and knowledge. This organization of information is characterized by the absence of prior detailed knowledge of the uses of the information. The ability of the user to access, reorganize, and utilize this repository is enriched by the capabilities of digital technology" 
  (adapted from Inter operability, Scaling, and the Digital Libraries Research Agenda)
• "Digital library is a concept that has different meanings in different communities. To the engineering and computer science community, digital library is a metaphor for the new kinds of distributed data base services that manage unstructured multimedia data. To the political and business communities, the term represents a new marketplace for the world's information resources and services. To futurist communities, digital libraries represent the manifestation of Wells' World Brain. The perspective taken here is rooted in an information science tradition." 
  (Gary Marchionini)
• "A digital library is a distributed technology environment which dramatically reduces barriers to the creation, dissemination, manipulation, storage, integration, and reuse of information by individuals and groups."

(Edward A. Fox , editor, Source Book on Digital Libraries, pg. 65)
• "A digital library is a machine readable representation of materials which might be found in a university library together with organizing information intended to help users find specific information. A digital library service is an assemblage of digital computing, storage, and communicate machinery together with the software needed to reprise, emulate, and extend the services provided by conventional libraries based on paper and other material means of collecting, storing, cataloging, finding, and disseminating information."

(Edward A. Fox , editor, Source Book on Digital Libraries, pg. 65)
• "an organized data base of digital information objects in varying formats maintained to provide unmediated ease of access to a user community, with these further characteristics:

- an overall access tool (e.g. a catalog) provides search and retrieval capability over the entire data base;  
- organized technical procedures exist through which the library management adds objects to the data base and removes them according to a coherent and accessible collections policy." 
(Peter Graham, Rutgers University Libraries) 
• "A library that has been extended and enhanced by the application of digital technology. Important aspects of the digital library that may be extended and enhanced include :

 - Collections of the library  
 - Organization and management of the collections  
 - Access of the library items and the processing 
   of the information contained in the items  
 - Communication of information about the items " 
(Smith, 1995) 

Digital Library related terms/glossary

• digital archive:  a digital library which is intended to be maintained for a long time, i.e. periods longer than individual human lives and certainly longer than individual technological epochs.  (Sometimes formerly also "digital research library.")
• digital preservation:  preservation of artifactual information by digitizing its image (e.g. scanning a manuscript page, digitally photographing a vase, or converting a cylinder recording to digital form).
• electronic preservation:  preservation of information that is in digital (that is, electronic) form, i.e. the techniques associated with refreshing, migration and assurance of integrity.

Digital Preservation techniques:

• Refresh: to copy digital information from one long-term storage medium to another of the same type, with no change whatsoever in the bit stream (e.g. from a decaying 800 bpi tape to a new 800 bpi tape, or from an older 5 1/4" floppy to a new 5 1/4" floppy).
  
  
• "Modified refreshing" is the copying to another medium of a similar enough type hat no change is made in the bit pattern that is of concern to the application and operating system using the data, e.g. from an 800 bpi tape to a 1600 bpi tape or to a "square", cartridge, tape; or from a 5 1/4" floppy disk to a 3 1/2" floppy disk.
  
  
• Migrate: to copy data, or convert data, from one technology to another, whether hardware or software, preserving the essential characteristics of the data; generally forward in time.  (At the moment, it is recognized, this final qualifier begs many questions.)  Examples:  conversion of XyWrite w/p files to Microsoft Word; conversion of ClarisWorks v3 spreadsheet files to Microsoft Excel v4 files; conversion of binary tape images of survey research

multi-punched tab cards to a data base format; copying an 800 bpi tape file to a sequential disk file; converting a DOS FoxPro data base to a Visual Basic database for Windows 95;  converting a PICT image to a TIFF image; converting a ClarisWorks for Windows v4 w/p file to a Macintosh ClarisWorks v4 file. 

Examples can be given, as here, for cases known to be required; the longer term preservation problem is to prepare for forward migrations when the future technologies are unknown.
 

• Emulate: (find and use better Comp SCI terms here, probably) in hardware terms, the creation of software for a computer that reproduces in all essential characteristics (as defined by the problem to be solved) the performance of another computer of a different design.  Computers may emulate earlier computers in order to provide backward compatibility, or may emulate a future computer in order to provide a software development environment while the newer computer is still being fabricated.

In software preservation terms, the creation of software that analyzes the software environment of a document such that it can provide a user interface to the document that substantially reproduces the essential characteristics of the document as it was created by its originating software.
 

• Document: (use sense that Apple began to use, with Macintosh; anything manipulated by an application; find their definition and build on it.  Note Dublin Core [and other] use of "document like object").

 
• Authenticate: of users, to verify that network users are in fact who they identify themselves to be; of documents, to validate the integrity of a document with respect to its original authorized creation.

 
• Authentication: (of a resource--i.e. of data, not people)

 
• Authenticity: (of a resource--i.e. of data, not people)
  
  
• Integrity: synonym of authenticity (of a resource--i.e. of data, not people)