VARIABLE MEANING
CONTENT_LENGTH The length of POST data sent by the client.
CONTENT_TYPE For POST and PUT requests, this is the type of data being sent.
PATH_INFO extra path information
PATH_TRANSLATED Path info for Web document
QUERY_STRING query string
REQUEST_METHOD The type of request being made. Normally this is either GET or POST.
SCRIPT_NAME The path to the script used to refer to it in a URL.