The server has fulfilled the request but does not need to return an entity-body and might want to return updated meta-information. The response MAY include new or updated meta-information in the form of entity-headers, which if found SHOULD be associated with the requested variant.
If the client is a user agent, it SHOULD NOT change its document view into the one that caused the sending of the request. This response is primarily intended to allow input for actions to take place without causing a change of the user agent active document view, although any new or updated meta-information SHOULD be applied to the document currently in the user agent active view.
The 204 response MUST NOT include a message-body, and is thus always terminated by the first empty line after the header fields.