title: How to decide between Message Contract and Data Contract in WCF?
body: <p>I am reading so many things to understand various things in WCF. </p>
  
  <p>Very soon, actually, i want to move/convert existing WSE3 web services to WCF. In existing WSE web services, I have some (data) classes that model entities in our environment.</p>
  
  <p>While transforming those classes, should I use Data Contract/Data Member attribute or the MessageContract attribute?</p>
  
  <p><strong>1. How to decide between Message Contract and Data Contract in WCF?
  2. Does type of binding (like basicHttpBinding) has any role in this decision? 
  3. Does proxies created at client side (when we add web reference) change significantly depending on the Data or Message Contract?</strong></p>
  
  <p>(PS: I am trying to find a way so that existing WSE clients should be able to consume the WCF service without much alterations/modifications. Is it possible to use the current proxies generated from ASMX web services, to connect to the new WCF service just by setting URL of the proxy to WCF service?)</p>