What are the differences between php magic variables __METHOD__ and __FUNCTION__

class Test{
 public function doit(){
 echo __FUNCTION__;
 }
 public function doitAgain(){
 echo __METHOD__;
 }
}
$obj = new Test();
$obj->doit();
echo '';
$obj->doitAgain();
?>

Output result: doit Test::doitAgain