title: what is qsTr in PyQt/QT?
body: <p>I'm new in the world of Qt/PyQt/QML.</p>
  
  <p>I'm creating a simple calculator using PyQt5 and QML.
  In QML title is assigned by like below instead of a string.</p>
  
  <pre><code>title : qsTr("PyQt5 Love QML")
  </code></pre>
  
  <p>I've no idea what is the use of <strong>qsTr</strong> and What is the advantage of it.</p>