Ok, I just wanted to clarify between 2 thinks that you mentioned and I
don't feel were explained in a finite manner.

PHP has scopes just like other languages, you can find every thing you
want to know about that at http://us2.php.net/variables.scope

The other thing you stumbled upon is called Access Modifiers. Access
Modifiers are used in Object Oriented Programming(OOP) and are
available in PHP as of version 5. Which a decent explanation of the
different modifiers is found at http://www.hudzilla.org/phpbook/read.php/6_7_0
.. For sure if you have not done any OOP I would suggest reading up on
the subject.

Best Regards,

Casey