Validation v/s Form_Validation

[eluser]Yash[/eluser]
In old validation

Code:

$this->input->post('name');
$_POST['name'];
$this->validation->name;

In Form validation

Code:

$this->input->post('name');   //works
$_POST['name'];      //works
$this->form_validation->name;  //not working?

This is not a Qs really just curious why not we can't access field like this.