What does zero mean in Handler.sendEmptyMessage(0)
<p>I am learning Android and I am stuck at this statement.
From google:</p>

<blockquote>
  <p>Sends a Message containing only the what value.</p>
  
  <p>Returns</p>
  
  <p>Returns true if the message was successfully placed in to the message
  queue. Returns false on failure, usually because the looper processing
  the message queue is exiting.</p>
</blockquote>

<p>Someone please explains for me what the Message containing zero will do. Thanks</p>
