specification.

In PHP, the request is represented by some global variables (``$_GET``,

``$_POST``, ``$_FILE``, ``$_COOKIE``, ``$_SESSION``, ...) and the response is

``$_POST``, ``$_FILES``, ``$_COOKIE``, ``$_SESSION``, ...) and the response is

generated by some functions (``echo``, ``header``, ``setcookie``, ...).

The Symfony2 HttpFoundation component replaces these default PHP global

* ``attributes``: no equivalent - used by your app to store other data (see:ref:`below<component-foundation-attributes>`)

* ``files``: equivalent of ``$_FILE``;

* ``files``: equivalent of ``$_FILES``;

* ``server``: equivalent of ``$_SERVER``;

1. Customize the error templates of the different error pages (explained below);

2. Replace the default exception controller ``TwigBundle::Exception:show``

2. Replace the default exception controller ``TwigBundle:Exception:show``

with your own controller and handle it however you want (see

:ref:`exception_controller in the Twig reference<config-twig-exception-controller>`);