$ SERVER functions

what are they all and what do they do

[whatson]

e.g.
$_SERVER['SCRIPT_NAME'] = file name after the domain
$_SERVER['SCRIPT_FILENAME'] = complete filename

What are the other ones and what do they do?

[SteveWh]

These are variables whose values are automatically filled in before your script starts to execute. You can use them anywhere in your scripts. See the list at
[php.net...]

If you plan to write a lot of PHP code, you can download the documentation from here: [php.net...]
In Windows, I use the .chm Help file with user notes. In Linux, I use the "many HTML files" version. I find both very usable.

[rocknbil]

A FYI, $_SERVER is one of the PHP superglobals (not functions, $_SERVER is a global array available to any part of a program,) and in other languages are called environment variables. They are extracted, and changed based on, the server software environment.

You can see them any time with

<?php
phpinfo();
?>