title: What does it mean to attach a tty/std-in-out to dockers or lxc?
body: <p>I read some docker docs and I do not understand what it might mean to</p>
  
  <ul>
  <li>attach a tty</li>
  <li>attach std-in and std-out</li>
  </ul>
  
  <p>for these purposes, I see that <code>-i</code> and <code>-t</code> flags are use.</p>
  
  <p>What does this process mean?</p>