Neither requires the other, but their co-evolution make them natural complements in the metadata architecture for the Web. The Dublin Core community and the RDF community have a number of members in common, and they have evolved together. A datamodel is an abstract representation of the part of the world that a system is designed to service. In particular, Relation and source are used to indicate a connection with another resource of any type. Creator, Contributor and Publisher relate the present resource to a party who has some responsibility for it.
Coverage relates the present resource to a place or to a time-period.
In this way, it is possible that a web of DC descriptions of resources will be constructed, with each resource at the centre of a fan of descriptive arcs, but connected via one of these relationships to other resources with their own fans. As its name implies, the Dublin Core is a starting place, not a final word. It is expected that local applications will add elements to meet local or community needs. Local extensions should be clearly distinguished from the Dublin Core through the use of a notational mechanism, such as using a prefix or namespace. Elements which are part of a local extension will not normally be useful to others that they have not been subject to the cross-community consensus building process that has brought the Dublin Core element set to its current state.