Reflection was introduced in PHP 5 to inspect and to retrieve information and reverse-engineer classes, interfaces, functions and methods as well as extensions during runtime.

Snippets:

How to create an instance of a class using reflection in PHP:

// this code does the same as: $instance = new ClassName();
$class = new ReflectionClass("ClassName");
if ($class->isInstantiable())
	$instance = $class->newInstance();