Types can themselves be identified by URIs as for example is the case for RDF . Anchor An area within a resource that can be the source or destination of zero, one or more links . An anchor may refer to the whole resource, particular parts of the resource, or to particular manifestations of the resource. The role adopted by an application when it is supplying resources or resource manifestations. Proxy A proxy is an intermediary which acts as both a server and a client for the purpose of retrieving resources or resource manifestations on behalf of other clients.
Clients using a proxy know the proxy is present and that it is an intermediary.
Gateway A gateway is an intermediary which acts as a server on behalf of some other server with the purpose of supplying resources or resource manifestations from that other server. Clients using a gateway know the gateway is present but does not know that it is an intermediary. An HTTP to FTP gateway Message A unit of communication exchanged between equivalent network layers or services, located at different hosts. Request A message describing an atomic operation to be carried out in the context of a specified resource. Response A message containing the result of an executed request.