Emacs Orgmode: hiding other items in the tree

Question

I have an org file, that looks like:

* Item 1
** Subitem 1.1
* Item 2
** Subitem 2.1
This text from Subitem 2.1 
** Subitem 2.2

I am editing text under Subitem 2.1. Is there a way to hide everything from the screen, except Subitem 2.1, so ideally while editing the text I just want to have a view like:

** Subitem 2.1
This text from Subitem 2.1

Answer 1

What I need is:

C-x n s     (org-narrow-to-subtree)
    Narrow buffer to current subtree. 

To widen the buffer again, use C-x n w

(from http://orgmode.org/manual/Structure-editing.html)
P.S. I was googling using a wrong word: "hide" instead of "narrow" :)