PHP Registry Pattern

[Zick]

I've found the piece of code below in several places around the web and even here on Stack Overflow, but I just can't wrap my head around it. I know what it does, but I don't know how it does it even with the examples. Basically it's storing values, but I don't know how I add values to the registry. Can some try to explain how this code works, both how I set and retrieve values from it?\[code\]class Registry {private $vars = array(); public function __set($key, $val) { $this->vars[$key] = $val; } public function __get($key) { return $this->vars[$key]; }}\[/code\]