title: Use of Interface and Abstract Class for Specific to my application?
body: <p>I am asp.net programmer and i have two application one is like eCommerce application like eBay site and other is management like say store management system say like bigbazzar or any book store etc .</p>
  
  <p>Now i wanted to implement interface and abstract class in my projects.i have read about the abstract class and interface and know hoe to use therotically.but am looking for the real world or practical example of both which is relevant to my applications.(i.e. for eCommerce &amp; store management)
  I have search a lot for sample web eCommerce and management where interfaces and abstract classes are beautifully used.
  Can any body help me how to use interface and abstract class used in my eCommerce &amp; store management application.</p>
  
  <p>It is good if you can share any relevant (i.e. ecomm and store management) application or project where abstract class and interface used ,so i can easily correlate with my project due to relevancey. </p>