title: What does print()'s `flush` do?
body: <p>There is a boolean optional argument to the <code>print()</code> function <code>flush</code> which defaults to False.</p>
  
  <p>The documentation says it is to forcibly flush the stream.</p>
  
  <p>I don't understand the concept of flushing. What is flushing here? What is flushing of stream?</p>