Collection<String>

Question

Whats the main difference between a Collection of String (Collection)and a simple, plain collection?

Answer 1

A plain Collection will accept any kind of Object, while a Collection<String> will only accept Strings.

If instead of String you had a Collection of something that could be extended, say Collection<List>, then the collection would accept anything that is a subtype of List. Sun's Java Tutorial on Generics is a good place to go to learn more.

Answer 2

Once compiled, nothing... But it can help you not to try to put any other object than a String while coding, and you don't have to cast back the objects that you retrieve from the collection.