title: What is the real advantage of returning ICollection<T> instead of a List<T>?
body: <p>I've read a couple of blog post mentioning that for public APIs we should always return ICollection (or IEnumerable) instead of List. What is the real advantage of returning ICollection instead of a List?</p>
  
  <p>Thanks!</p>
  
  <p>Duplicate: <a href="https://stackoverflow.com/questions/398903/what-is-the-difference-between-list-of-t-and-collectionof-t">What is the difference between List (of T) and Collection(of T)?</a></p>