Variable Description
DOCUMENT_ROOT Document root
HTTP_ACCEPT Accept header of an HTTP request
HTTP_ACCEPT_ENCODING Accepted encoding (deflate or gzip)
HTTP_ACCEPT_LANGUAGE Accept-Language from HTTP header
HTTP_CONNECTION Connection header of the HTTP request
HTTP_HOST Internet host
HTTP_USER_AGENT Client initiating web request
PATH Directories the server looks
REMOTE_ADDR Address of the client
REMOTE_PORT Port of client
SCRIPT_FILENAME Absolute path of script
SERVER_ADDR Server's address
SERVER_ADMIN Admin of server
SERVER_NAME Server name set
SERVER_PORT Port the web server is running on
SERVER_SIGNATURE Version of the server software
SERVER_SOFTWARE Server's identification string, found in HTTP header
GATEWAY_INTERFACE Version of the CGI spec used
SERVER_PROTOCOL Protocol server is currently using
REQUEST_METHOD Request method, such as GET, PUT, POST, etc.
QUERY_STRING Query string if one exists
REQUEST_URI Uniform Resource Identifier
SCRIPT_NAME Path and name for the current script
PATH_TRANSLATED Absolute path on the web server's file system
PHP_SELF Location of PHP script relative to document root
