Magento's Helper classes contain utility methods that will allow you to perform common tasks on objects and variables.

	$helper = Mage::helper('catalog');

Each Module has a default Data Helper class. The following is equivalent to the above:

	$helper = Mage::helper('catalog/data');

Most Helpers inherit form Mage_Core_Helper_Abstract, which gives you several useful methods by default. 

	$translated_output =  $helper->__('Magento is Great'); //gettext style translations
	if($helper->isModuleOutputEnabled()): //is output for this module on or off?