The Set interface inherits its methods from Collection (java.util.Collection) and contains only those methods. In addition to sets, there are queues (java.util.Queue) and maps (java.util.Map).

Since the introduction of the Java Collections Framework with JDK 1.2 , I have used Java arrays significantly less frequently than I used to. However, I still use arrays occasionally, often ...

Why should you use Collections class methods rather than similarly named fields to obtain empty collections? Type safety makes the crucial difference.