cakephp中链接和postLink之间的区别

I am new to cakephp. Please bear with me. I want to know what is the difference between

$this->Html->link();

And

$this->Form->postLink();

As i have seen both of them will output anchor tag only. What makes the use of postLink() over link() ????

In the first case (Html->link()), you have only a link to a URL. If it starts with "http://", it is treated as external, else it should follow the convention controller/action/view.

In the second case (Form->postLink()), you create a <form> element so it will be passed in $_GET[] or $_POST[] depending on the options you set - default is POST.

All the info here from Cakephp API.