title: Thread.Sleep vs Task.Delay?
body: <p>I know that <code>Thread.Sleep</code> blocks a thread. </p>
  
  <p>But does <code>Task.Delay</code> also block? Or is it just like <code>Timer</code> which uses one thread for all callbacks (when not overlapping)?</p>
  
  <p><em>(<a href="https://stackoverflow.com/questions/15341962/how-to-put-a-task-to-sleep-or-delay-in-c-sharp-4-0"><strong>this</strong></a> question doesn't cover the differences)</em></p>