A standard set of 15 interoperable  metadata  elements designed to facilitate the description and recovery of document-like resources in a networked environment.  

Dublin Core is the result of an international cross-disciplinary consensus achieved through the ongoing efforts of the Dublin Core Metadata Initiative (DCMI), aimed at providing a foundation for  standardized bibliographic description  of information resources available via the Internet. In 2007, the Dublin Core Metadata Element Set was published by the International Organization for Standardization. 

The descriptive elements are:

Title (name given to the resource)

Creator (entity primarily responsible for making the content of the resource)

Subject (topic of the content of the resource, typically expressed as keywords, key phrases, or classification codes)

Description (abstract, table of contents, free-text account of the content, etc.)

Publisher (entity responsible for making the resource available)

Contributor (entity responsible for making contributions to the content of the resource)

Date (typically associated with the creation or availability of the resource)

Type (nature or genre of the content of the resource)

Format (physical or digital manifestation of the resource)

Identifier (an unambiguous reference to the resource within a given context, such as the URL, ISBN, ISSN, etc.)

Source (reference to a resource from which the present resource is derived)

Language (the language of the intellectual content of the resource)

Relation (reference to a related resource)

Coverage (extent or scope of the content of the resource)

Rights (information about rights held in and over the resource)