Page Comparison

The 1xx (Informational) class of status code indicates an interim
   response for communicating connection status or request progress
   prior to completing the requested action and sending a final
   response.

The 2xx (Successful) class of status code indicates that the client's
   request was successfully received, understood, and accepted.

 The 300 (Multiple Choices) status code indicates that the target
   resource has more than one representation, each with its own more
   specific identifier, and information about the alternatives is being
   provided so that the user (or user agent) can select a preferred
   representation by redirecting its request to one or more of those
   identifiers.  In other words, the server desires that the user agent
   engage in reactive negotiation to select the most appropriate
   representation(s) for its needs ().

The 301 (Moved Permanently) status code indicates that the target
   resource has been assigned a new permanent URI and any future
   references to this resource ought to use one of the enclosed URIs.
   Clients with link-editing capabilities ought to automatically re-link
   references to the effective request URI to one or more of the new
   references sent by the server, where possible.

The 302 (Found) status code indicates that the target resource
   resides temporarily under a different URI.  Since the redirection
   might be altered on occasion, the client ought to continue to use the
   effective request URI for future requests.

The 303 (See Other) status code indicates that the server is
   redirecting the user agent to a different resource, as indicated by a
   URI in the Location header field, which is intended to provide an
   indirect response to the original request.  A user agent can perform
   a retrieval request targeting that URI (a GET or HEAD request if
   using HTTP), which might also be redirected, and present the eventual
   result as an answer to the original request.  Note that the new URI
   in the Location header field is not considered equivalent to the
   effective request URI.

The 305 (Use Proxy) status code was defined in a previous version of
   this specification and is now deprecated (Appendix B).

The 306 status code was defined in a previous version of this
   specification, is no longer used, and the code is reserved.

The 307 (Temporary Redirect) status code indicates that the target
   resource resides temporarily under a different URI and the user agent
   MUST NOT change the request method if it performs an automatic
   redirection to that URI.  Since the redirection can change over time,
   the client ought to continue using the original effective request URI
   for future requests.

The 400 (Bad Request) status code indicates that the server cannot or
   will not process the request due to something that is perceived to be
   a client error (e.g., malformed request syntax, invalid request
   message framing, or deceptive request routing).