I slightly remember from my age old Java days, that there was an RequestScope object and a Response object. RequestScope contained the POST headers sent from browsers and the GET arguments. Well, it's a few years ago, might be inaccurate.
What kind of scopes for request and response are there in PHP environment? Well I think there's a $_GET and $_POST (sorry if wrong, I'm just a few days new to PHP). Is that the only thing? Where does the output go?
This works a bit differently in most PHP environments than you're describing from Java. PHP uses several "super-global" arrays to contain request, environment and system information: $_GET, $_POST, $_COOKIE, $_REQUEST, $_SESSION, $_SERVER, $_FILE.
In general, the response is simply the output you write to STDOUT as the script processes. It is possible to use output buffering to help control what is sent to the client, but there is no native support for a response "scope" or "object".
RequestScope contained the POST headers sent from browsers and the GET arguments.
FYI, There is a super-global that contains both the $_GET and $_POST. It is $_REQUEST.