title: In C#, what does task.oncomplete do?
body: <p>I don't understand a sentence in the book C#5.0 in a nutshell P570, it says:</p>
  
  <blockquote>
    <p>If s synchronization context is present, oncomplete automatically
    captures it and posts the continuation to that context. This is very
    useful in rich client applications, as it bounces the continuation
    back to the UI thread.</p>
  </blockquote>
  
  <p>I don't know what does "bounce back" mean, is the thing in oncomplete() done in the main thread?</p>