title: Need someone to explain the SharedPreferences class
body: <p>Android provides the <code>SharedPreferences</code> class, and we need to create an XML file to store the value of each Preferences (that is what I know). But I don't know, after using SharedPreferences.Editor to modify value, where the modified values are stored? I can't see any change in the XML file.</p>
  
  <p>Also, what are the differences between <code>apply()</code> and <code>commit()</code>, <code>getSharedPrefences</code> and <code>getPreferences</code>?</p>