what $string = $this->load->view('myfile', '', true) exactly does?

[eluser]mddd[/eluser]
Yes your code is correct. With your code, you are loading the view (with your title and heading) and saving that in $string.
So now you can use $string for whatever you need. Do some processing with it, display it as part of another view, etc.

If you wanted to just output the view to the browser you would use $this->load->view('blogview', $data);