title: What is the purpose of Looper and how to use it?
body: <p>I am new to Android. I want to know what the <code>Looper</code> class does and also how to use it. I have read the Android <a href="http://developer.android.com/reference/android/os/Looper.html" rel="noreferrer">Looper class documentation</a> but I am unable to completely understand it.
  I have seen it in a lot of places but unable to understand its purpose. Can anyone help me by defining the purpose of <code>Looper</code> and also by giving a simple example if possible?</p>