what is use of loadlayout and renderlayout and what can they do?

Question

what is loadlayout() and renderlayout() do ? in controller'S Function

 public function viewAction()
 {
 $this->loadLayout();
 $this->renderLayout();
 }

Answer 1

$this->renderLayout(); get layout output and process this output to response body and append response

$this->loadLayout(); creates XML tree at backend.