Modx 2 How does getService works?

modx->getService($name, $class= '', $path= '', $params= array ())

name = name to be assigned to modx->$name and modx->services[$name]

class = classname (resolving to "classname".class.php)

path = path to look for class

params = array of value pass to class.

Example:

getService("login", "Login", corepath."/components/login", ...);

Resolve to:

core/components/login/Login.class.php

initiate class __construct(modxobject, $params);