title: What is an event loop in Qt?
body: <p>I have understood the following regarding QApplication's <code>exec</code> function:</p>
  
  <blockquote>
    <p>QApplication exec starts the main event loop.
     It launches the GUI. It processes the signals and calls appropriate slots on receiving them. It waits until exit is called and returns the value which was set in exit.</p>
  </blockquote>
  
  <p>Now, when we say event loop, does it mean that there is some while loop running in the internal code of Qt, and in that while loop the method of handling signals and slots is written?</p>