title: What does `:location => ...` and `head :ok` mean in the 'respond_to' format statement?
body: <p>I am using Ruby on Rails 3 and I would like to know what the <code>:location =&gt; ...</code> and <code>head :ok</code> statements mean in following code, how they work and how I can\should use those.</p>
  
  <pre><code>respond_to do |format|
      format.xml  { render :xml =&gt; @user, :status =&gt; :created, :location =&gt; @user }
  end
  
  respond_to do |format|
      format.xml  { head :ok }
  end
  </code></pre>