title: Why do we need inheritance in JPA (ORM)?
body: <p>I have not yet used inheritance while using any ORM frameworks. I was trying to understand it through <a href="http://en.wikibooks.org/wiki/Java_Persistence/Inheritance" rel="nofollow">this</a> article but did not understand why and when exactly is inheritance needed/involved.</p>
  
  <p>It is a bit tricky and seems unusual, since relational databases have no concept of inheritance.</p>
  
  <p>What is the advantage of using inheritance in ORM? Are there any specific situations where it is mandatory?</p>
  
  <p><sub>Please give an example(s), if possible.</sub></p>