title: What is difference between default and custom serialization?
body: <p>What is default and custom serialization ?
  Default serialization is appropriate if physical and logical representation aren't differ and if aren't it need to use custom serialization.
  But I couldn't get what's really default and custom.</p>
  
  <pre><code>//Default serialization form :`
      public final class StringList implements Serializable {
          private int size = 0;
          private Entry head = null;
      }
      private static class Entry implements Serializable {
          String data;
          Entry next;
          Entry previous;
      }
      ... // Remainder omitted
  }
  
  //Custom serialization form
      public final class StringList implements Serializable {
          private transient int size = 0;
          private transient Entry head = null;
  
      // No longer Serializable
      private static class Entry {
          String data;
          Entry next;
          Entry previous;
      }
  }
  </code></pre>
  
  <p>So is there well explained example ?</p>