title: extjs 4.1 When do I use a proxy on a store and when on a model?
body: <p>There are two ways to use proxies in extjs 4.1 (server proxies in my case), one can tie it to a model or tie it on a store.</p>
  
  <p>I am a bit confused about the usage: What is the difference between tieing a proxy to a store, and tieing it to a model?</p>
  
  <p>What situations would one use one way or the other? </p>