A request is forwarded only forwards the request to the same WEB application components, and redirection can also be redirected to the same site in different application resources, and even can be directed to an absolute URL.
Redirection can see the URL of the target page, the page URL forwarding can only see the first visit, after all there is a server to do the work.
Request response between caller and callee objects share the same request and response objects, redirect the caller and callee belong to two separate access request and response process.
Must be added after the jump redirect return, or else jump though the page, but also performs jump behind the statement, forwarding is performed jump page, the following code would not be executed.
