The java.util package includes a set of interfaces and classes for collections.The interfaces include List and Queue (for linear collections), Set and Map (for unordered collections), SortedSet and SortedMap (for sorted collections), and Collection (for high-level operations on implementing collections). The implementing classes include ArrayList, LinkedList, Vector, and Stack (as lists), LinkedList (as a queue), HashSet (as a set), HashMap (as a map), TreeSet (as a sorted set), and TreeMap (as a sorted map).
Interfaces are one piece of the connective tissue for organizing a framework of collections. The other piece is the iterator.
Chapter 14 examines the organization and use of Java's collection resources and shows how interfaces, classes, and iterators can be used effectively to solve problems.