A DOI® (Digital Object Identifier) is a name (not a location) for an entity on digital networks. It provides a system for persistent and actionable identification and interoperable exchange of managed information on digital networks.
From the DOI System website (retrieved 11:58, 28 April 2007 (MEST)):
The DOI System is for identifying content objects in the digital environment. DOI® names are assigned to any entity for use on digital networks. They are used to provide current information, including where they (or information about them) can be found on the Internet. Information about a digital object may change over time, including where to find it, but its DOI name will not change.
The DOI System provides a framework for persistent identification, managing intellectual content, managing metadata, linking customers with content suppliers, facilitating electronic commerce, and enabling automated management of media. DOI names can be used for any form of management of any data, whether commercial or non-commercial.
The system is managed by the International DOI Foundation, an open membership consortium including both commercial and non-commercial partners, and has recently been accepted for standardisation within ISO. Over 25 million DOI names have been assigned by DOI System Registration Agencies in the US, Australasia, and Europe.
Using DOI names as identifiers makes managing intellectual property in a networked environment much easier and more convenient, and allows the construction of automated services and transactions.
DOI's are a kind of URN (RFC 2141 URN Syntax) and the he DOI System uses as its naming syntax the NISO standard Z39.84 "Syntax for the DOI". The DOI System uses for its name resolution the Handle System (IETF RFCs 3650, 3651, 3652).
See also: ISBN (The traditional book identifier)
How to make links with a DOI ?
(this is a FAQ)
Simply append the DOI number to this URL:
E.g. for an article with the following DOI