{* display value of page from URL (GET) http://www.domain.com/index.php?page=foo *}
{$smarty.get.page}

{* display the variable "page" from a form (POST) *}
{$smarty.post.page}

{* display the value of the cookie "username" *}
{$smarty.cookies.username}

{* display the server variable "SERVER_NAME" *}
{$smarty.server.SERVER_NAME}

{* display the system environment variable "PATH" *}
{$smarty.env.PATH}

{* display the php session variable "id" *}
{$smarty.session.id}

{* display the variable "username" from merged get/post/cookies/server/env *}
{$smarty.request.username}