Enumeration is an old twig from Java1.0. About the difference betweem Enumeration and Iterator, here is what the Enumeration API tells us :
The functionality of this interface is duplicated by the Iterator interface. In addition, Iterator adds an optional remove operation, and has shorter method names. New implementations should consider using Iterator in preference to Enumeration.
Like Christophe said, an Iterator can do the same an Enumeration can do, with added optional removal of elements. In fact, you can implement one backed by the other:
Note that the remove() method throws an UnsupportedOperationException; this is done a lot when an interface defines an optional method and you wish not to really implement it. You must provide an implementation though because the interface still defines the method, so throwing this exception is the best implementation.