(1) A class or construct that is used to step through a collection of objects one at a time.
(2) In a collaboration template's activity diagram, a specialised form of subdiagram that is analogous to a "for" loop and that allows a collaboration to perform an operation on all the attributes of a business object or on all the elements of a business object array. Also, the activity diagram symbol that embeds a reference to a nested diagram that implements such a looping operation, and the diagram that contains the looping behavior.
(3) In SQLJ, an object that contains the result set of a query. An iterator is equivalent to a cursor in other host languages.