See http://greenbytes.de/tech/webdav/draft-ietf-httpbis-p2-semantics-26.html#rfc.section.6.4.p.2:
There are several types of redirects:
Redirects that indicate the resource might be available at a different URI, as provided by the Location field, as in the status codes 301 (Moved Permanently), 302 (Found), and 307 (Temporary Redirect).
Redirection that offers a choice of matching resources, each capable of representing the original request target, as in the 300 (Multiple Choices) status code.
Redirection to a different resource, identified by the Location field, that can represent an indirect response to the request, as in the 303 (See Other) status code.
Redirection to a previously cached result, as in the 304 (Not Modified) status code.